I sit alone at a reproduction antique table under a fake chandelier in the dining room at the Gore Hotel in Kensington. There is no sign of Jonathan Franzen; nor of anyone else. The place is entirely empty.

While I wait, I look at what people are saying about Franzen on Twitter. There is a Times columnist moaning that Purity is a load of tripe. Someone else points out that Franzen has no black people in his novels. Others are incensed by his recent performance on Newsnight, in which he did what he often does — disparage the internet.

All this loathing is baffling. I have read and loved The Corrections (2001), Freedom (2010) and now Purity, the latter billed as a cross between Charles Dickens and Breaking Bad. It has kept me up every night for a week, and now that I’m done, I’ll miss its wit, its messed-up characters and its emotional complexity. It is a mystery how the man who wrote it could have become, in the words of the Los Angeles Review of Books, “with the possible exception of Kanye West — the most bitched about artist in America”.

It is nearly 2pm when the door opens and the great American novelist makes a modest entrance. He’s in an old navy fleece. His dark hair is tousled and even though it is going grey he looks closer to 40 than 56. He is wearing the same heavy black glasses that, last time he was in London promoting a novel, were snatched from his nose by a prankster who proceeded to jump into the Serpentine lake, just minutes round the corner from where he stands now.

Franzen has barely sat down when the waiter, evidently excited to be given something to do at last, is bearing down on us, pad in hand. “I would love some still water if I may, please,” says Franzen, all politeness and diffidence. “And maybe something along the lines of a Diet Coke?”

Does he know about Lunch with the FT, I ask. “I think my eye has literally fallen on it.” Franzen speaks slowly and sounds so uncomfortable, I conclude he’s trying to be nice but is a rotten liar.

I make some disparaging remarks about the restaurant’s frumpy decor but he declines to join in. For him its unpopularity is an advantage. “There’s a certain sameness to high-end restaurant experiences, at least in New York, I’m kind of nauseated by the clientele. They’re total 1 per centers and they’re doing it every day and there’s something kind of just disgusting and like the pigs in Animal Farm about the whole thing.”

But since the rip-roaring success of The Corrections 14 years ago, isn’t he a 1 per center himself? “I am literally, in terms of my income, a 1 per center, yes,” he says, his eyes not on me but on the empty table next to us. “I spend my time connected to the poverty that’s fundamental to mankind, because I’m a fiction writer.”

He doesn’t write about poverty, I protest. He writes about the angst of people like him and the people he knows. Franzen gives the neighbouring table top a weary look. “That’s a quotation from Flannery O’Connor, by the way.”

Bistro One Ninety, Gore Hotel 190 Queen’s Gate, Kensington, London SW7 Pre-theatre menu (tortellini, grey mullet) x 2 £49.90

Fruit £8

Diet Coke x 2 £7

Mint tea £4

Total (inc service and VAT) £77.50

While I smart, he goes on: “I’m a poor person who has money.”

Franzen doesn’t spend anything. The fleece he is wearing is 10 years old. He doesn’t like shopping and hates waste. Upstairs in the fridge in his hotel room are the leftovers from meals, all of which he will eat in due course. His only luxury is expensive kit for birdwatching.

“I don’t like to hire people to do work that I can do,” he says. So that means he does his own dusting in the New York apartment he shares with his girlfriend? Franzen looks slightly shifty. “We do have a cleaner, although even that I feel some justification because we pay her way more than is standard and she’s a nice Filipino woman who we treat very well and we’re giving her work.”

In a way this middle-class guilt is sweet. But it’s also absurd. By the same argument he should be employing as many people as possible.

“Something doesn’t sit well. It seems to me that I don’t want to lose touch with . . . Like I repainted our guest room this summer in our rather small house in Santa Cruz.”

Bingo, I want to shout. I love decorating too and start trying to interest him in my thoughts on masking tape, but he continues deadpan: “If I had hired someone, it would’ve been done better, and I was very sick of doing it by the end, and yet it seemed important. The first two coats I enjoyed and the third coat I was getting tired of it and the fourth coat was just sheer torture.”

While he has been talking we have each been given a large white bowl with a pair of tiny, shrivelled pastries in them and a jug of tepid, cloudy liquid on the side. Franzen eats his without comment, and I ask: does he understand why he makes people quite so cross? “Well, I have to acknowledge the possibility that I’m simply a horrible person.”

He recites the line with a practised irony. Evidently he acknowledges no such possibility at all.

“My other answers would all be sort of self-flattering, right? Because I tell the truth; people don’t like the truth.”

He tells me about a piece he wrote in the New Yorker in March about climate change and bird conservation in which he managed to alienate everyone, including bird watchers. “I pointed out that 25 years after humanity collectively tried to reduce its carbon emissions, they reached an all-time high last year; further pointed out that the people who say we still have 10 years to keep the average temperature from rising more than 2 degrees Celsius are, charitably, deluded or, uncharitably, simply lying. And, therefore, maybe we should rethink whether we want to be putting such a large percentage of our energies into what is essentially a hopeless battle.”

His idea of himself as a truth-teller is only partly why people find him so aggravating. There is something about the man himself, and his variety of superior maleness, that also annoys. Purity — which has a clever, lovably sarcastic woman as its heroine — has, nevertheless, enraged some feminists because there is a mad manipulative wife in it who makes her husband wee sitting down. The journalist Jenni Russell, for example, writes about how all Franzen’s books have dutiful men trapped in relationships with manipulative women. “It’s, like, where do you even begin with stuff like that? People who don’t know how to read fiction, they just shout words like ‘loathsome’ and ‘misogynist’ because they can’t deal with it. I fail to conform to the brutish, white, male stereotype and that is actually more enraging than the brutish, white, male stereotype. It’s the middle ground which is precisely what’s upsetting to people on the extremes.”

Our starters have been replaced by an almost entirely grey dish. The grey mullet lies on a grey bed of puréed artichokes with some whitish almonds.

This tastes weird, I say. “I’m not fussy about my food,” he says, taking a forkful. “It’s not bad.”

I ask if he saw the review of Purity in the Financial Times, which called it “middlebrow”. He says he never reads what people write about him. “I don’t know what ‘middlebrow’ even means. I think it’s threatening to commercial writers that someone who’s selling well is also getting literary respect, and it’s threatening to literary writers who don’t sell that somebody who’s literary also is getting commercial success.”

People who don’t know how to read fiction shout words like “misogynist” because they can’t deal with it

The thing that bothers me about his prose is not the popular bits but the clever-dick ones. In Purity, I took exception to a bilingual acrostic that allows Franzen (a Fulbright scholar in Berlin in the 1980s and translator of the work of obscure Austrian satirist Karl Kraus) to prove he’s smarter than his reader. “My agent didn’t get it, either,” he says. “Many, many people didn’t get it, and yet if the whole book were like that, you could say the writer’s being insufferable. But I think you have to have a few things that you have to kind of chew on to get.”

As if on cue, a loud cracking noise comes from his mouth. “Teeth hitting each other sort of sideways, glancing, catching,” he explains.

I ask if his teeth are bad, but he says they are very good. “I’m an American.”

He laughs and at once the ponderous gloom lifts. I get a glimpse of what are very good teeth indeed.

The levity doesn’t last: have I read Sapiens by Yuval Noah Harari, he asks? When I say I haven’t, he explains how the agrarian revolution was a mistake and argues we were happier as hunter-gatherers. With the internet, he implies, the same may apply. Is he really saying people were happier before the internet? He ducks the question and says instead: “I wasn’t. But I didn’t start feeling happy, really, until my forties.”

Happiness for Franzen is slightly problematical. He has often said the best writing comes from discomfort. He has had his share of pain — he has referred to the unhappiness of his 14-year marriage to writer Valerie Cornell — so I wonder, if he had always been as happy as now, would he . . . He cuts me off. “I was,” he says. “I was a smiling, smart, healthy, straight, Midwestern American male who went to decent public schools, what we call public schools, and an excellent college. I had everything it took.”

I have the feeling he’s playing with me, but still I plough on. Doesn’t he believe that if you haven’t felt pain you can’t write good fiction? “Apparently Paulo Coelho can.” He gives another dazzling smile that manages to be both beatific and slightly nasty. “I’m giving you a hard time. We’re talking about real novelists, who are going to be very sensitive, experience things intensely. That’s basically a recipe for pain. Things that a less sensitive person may experience as nothing create lasting scars.”

There is a lot of scar tissue in Purity. At one point the narrative switches into the first person, and a man and his wife have an exchange on the phone that is so mad, miserable, undignified and perverse, no one could have written it without having experienced something similar. When I read the passage I was slack-jawed with admiration, but couldn’t help wondering what his ex-wife would make of it. “I’m not the only one who’s been in a kind of nutty relationship. And so simply the fact of writing about a nutty relationship is not compromising anyone.”

So it’s fine, then? “No, there’s blood on the floor. It’s never fine. In a way, the thing I feel worst about is writing about my parents, even though I did all my writing after they were dead. It has more to do with their not having had an education that would have enabled them to appreciate what I was doing and why I was doing it.”

Then why betray people he loves? “Well, there’s a utilitarian argument to be made. People feel grateful and feel less alone with what had been a private torment, a private sorrow, a private shame.”

The waiter brings him a bowl of fruit salad so large he looks at it in dismay, as if fearing the inevitable waste.

“Would you like a little bit of this? Even just one bite would help,” he pleads, shovelling fruit on to my plate.

In The Corrections, Albert, who was based on Franzen’s father, was a benign if stern parental figure. In Purity parents get a tougher time of it. One mother shows a seven-year-old son her vagina. Another inflicts psychological violence by manipulating and stifling. I wonder if he would have written anything quite as dark if he had children himself?

Franzen sighs. “I’m sure everything would’ve been different. Maybe I would’ve been retired and working on a historical novel about the civil war and teaching fiction at Portland State University if I had had kids.”

I get the reproach, but it’s only later that I get the snobbery. There was a time, though, when Franzen wanted to have kids. According to the Guardian, for a while he considered adopting an Iraqi orphan so he could get to know young people. Was that true? “The story was the work of a nasty personage,” he says, then tells me what really happened. “There came a point when I was struggling with my fourth novel and I suspected the reason was that I had lost touch with the world, that I came from a strong family, and maybe I was meant to be a family man. But it’s a long way from that to adopting a war orphan to study young people. It fed into what everyone wanted to believe, which is I am an absolutely horrible person.”

He seems so weary of all this that I ask if he finds fame a burden. Has success made him less nice? No; he says it has made him less angry, and much less envious. “Writer’s envy is insane and knows nearly no bounds, but at some point it becomes obviously inappropriate.” These days if anyone else writes a good novel, he doesn’t feel upset; he is glad. The only trouble is that it hardly ever happens.

“I am very grateful to Haruki Murakami for writing The Wind-Up Bird Chronicle, I feel the same way right now about Elena Ferrante. I have trouble finding books that really do it for me.”

Envy is something his girlfriend, the writer Kathryn Chetkovich, is more straightforward about. In 2003, after the triumph of The Corrections, she wrote a devastating essay for Granta, on just how hard it was for her to bear her boyfriend’s success. If the boot had been on the other foot, Franzen says he would have felt differently, partly because he roots so seriously for “whoever I’m living with” but also because he is usually only competitive with men. In any case, he says, if he hadn’t been successful as a writer, he would have given up.

The waiter asks if he’d like coffee. “I’m good, thank you, right now.” It’s only when I see the transcript of our lunch and notice the phrase “I’m good” to mean “No, thank you”, I wish I’d challenged him on it. Franzen has strong feelings about certain words. He has written a whole essay on the evils of “then” as a conjunction, which strikes me as entirely baffling.

I try out a sentence: “Jonathan Franzen leaned forward, then he leaned back again.” What’s wrong with that? “That’s just a run-on sentence,” he says. “What you will find in bad English prose is, ‘He leaned forward then spoke again.’ ”

Sounds OK to me, I say. “Read my essay,” he says.

Lunch is nearly over, and there is one more thing I want to ask him. He has said that all decent novelists are changed by every book they write. So how did Purity change him? He stares at the table for so long with his eyes closed that I wonder if he has gone to sleep. “How I changed was I realised that I really am a fiction writer, I don’t have all that many years, and that I’ve got to find a way to write another couple of novels.”

As he gets up to leave, I tell him that we have covered so much ground in 90 minutes it will be a nightmare trying to write the lunch up. “Ask for more space,” he says. “Maybe they’d let you do a two-parter, the appetiser and the main course. Just saying.”

Lucy Kellaway is an FT columnist

Illustration by James Ferguson