I'm not asking for much. I just don't want to be sick in my mouth. I don't want to leave the cinema feeling like I've paid £7.50 to be mocked, patronised and kicked in the face. I don't want to be filled with despair at Hollywood's increasing inability to conceive of women in comedic films as anything other than self-obsessed babies with breasts. And I don't, most of all, want to spend two hours watching dreams and memories from my youth being trampled into humiliating self-parody. Is that too much to ask?

Judging from the hideous trailer and even more hideous scenes that have been leaked on the web, yes, all this is just beyond the capabilities of the pink-fringed, cliche-ridden, materialistic, misogynistic, borderline racist Sex and the City 2.

And depressingly, it's no surprise. After all, my God, did you see the first film? As Carrie herself would have once said – before she became the demented harpy she was init, one whose response to having been jilted at the altar was: "How am I going to get my clothes?" – could a cinematic experience be any worse than that SATC film (part 1) was? The answer from this Friday, when SATC 2 opens, looks set to being in the affirmative (and I warn you now, this article will be full of spoilers, spoilers of both the film and your memories of the show).

There's been a lot of nonsense written about SATC the TV series in recent weeks, often by journalists who never watched it (in fact, one writer of a recent piece cited that achievement as a point of pride before then listing his reasons for hating the show, reasons he presumably pulled out of his ass).

But the truth is, the show was fantastic: smart, funny, warm and wise, a far cry from the "middle-aged women having embarrassing sex with various unsuitable partners" cliche that the above writer used. It was about four smart women, three of whom had no interest in getting married. Candace Bushnell's original book on which the show was based was good, but the show was great. Yes, there were stupid puns (although I maintain that Carrie's response to Big when he said he was moving to California because he was tired – "If you're tired you take a napa, you don't move to Napa" – is pretty funny). And, yes, there was sex and shopping. But unlike in the films, that's not all there was, and that wasn't all the characters cared about. What elevated the show way above the normal chickflick tat, and way above the films, was that it had genuine emotional truth. It sang with lines that you knew had come from real life ("How can I have this baby? I barely had time to schedule this abortion" being quite possibly my all-time favourite) and plots that went beyond the limiting convention of cliche. Samantha's breast cancer, for example, showed not only how scary and sad cancer (obviously) is, but also how boring, sweaty and plain inconvenient it is, too.

But now, treacherously, the films confirm all the worst (and wrong) assumptions (men, mainly) made about the show and its (largely female) audience. The most humiliating example of this was the review of the first film in the New Yorker by Anthony Lane, one of my most revered journalists. Lane wrote: "I walked into the theatre hoping for a nice evening and came out as a hardline Marxist, my head a whirl of closets, delusions, and blunt-clawed cattiness . . . There is a deep sadness in the sight of Carrie and her friends defining themselves by . . . their ability to snare and keep a man." Oh, Anthony! You're right, but it wasn't always thus!

After I saw the first film and emerged from the cinema making a Munch-esque scream, I thought maybe Sarah Jessica Parker and Michael Patrick King (the show and film's writer and director) had been paralysed with fear by their foray into the cinema. But from recent interviews they have given, and how bad the second film looks, I'm really beginning to wonder. Did they just never get it? Was the show's genius a fluke that somehow slipped through their conventional, patronising net? Or have both been so blinded by the success of the show that they have lost sight of its original appeal? Simple comparisons between the films and the show give a hint of the answer.

In the TV show, the women (I refuse to refer to them as girls as they did a little in the TV series and a lot in the films) reprimanded Samantha for her occasional crackpot attempts to maintain her youth, and she always came round and loudly loved her looks. In the second film, she knocks back 44 pills every morning to "trick my body into thinking it's younger", she says triumphantly, and Carrie and Miranda look impressed. Miranda! Surely the woman who once said while buying her wedding dress on the TV show, "No white, no ivory, no nothing that says virgin. I have a child. The jig is up," will inject a little reality-establishing sarcasm here? No. She says, "I've tricked my body into thinking it's thinner – Spanx!" Again, Carrie nods approvingly. It's like being lobotomised with a pink teaspoon. (If this point about youth obsession now being de rigueur is not made clearly enough, behold the film poster, on which the four leads are so airbrushed not only do they not look like themselves, they don't even look human.)

Then there's the issue of race. The TV series was, quite rightly, criticised for rarely featuring non-Caucasian characters. The first film's nervy response to this was to include a black character, but as Carrie's assistant, played by Jennifer Hudson, who is cravenly grateful for Carrie's designer cast-offs, and then returns in the end to St Louis, where black people more belong. The second film goes even further, because King sends the characters to Abu Dhabi. Not since 1942's Arabian Nights has orientalism been portrayed so unironically. All Middle Eastern men are shot in a sparkly light with jingly jangly music just in case you didn't get that these dusky people are exotic and different. Even leaving aside the question of why anyone would go on holiday to Abu Dhabi, everyone who has ever watched a TV show knows that the first rule is: don't take characters out of their usual environment. The term "jump the shark" was even coined about the series-destroying episode of Happy Days in which the characters go on holiday and Fonzie water-skis over a shark. This rule was repeatedly proven in the TV series of Sex and the City as the weakest episodes always involved the women leaving New York (two forays to California, one to Atlantic City) and it is roundly proven here because the film-makers' knowledge of the Middle East begins and ends with Lawrence of Arabia, whereas part of the fun of the show was the in-the-know details about Manhattan. And speaking of Manhattan, the only ethnic minorities you see there are waiting behind counters to sell the women expensive handbags.

In the films the message is women want a ring at all self-abasing costs; in the show, Carrie rejected Aidan, who was perfect on so many levels, because she couldn't, no matter how hard she tried, bring herself to marry him. The show didn't judge her or him for that, nor did it get at her for being "old", the way the film does – it just showed how sad it was for both of them and how marriage takes more than just the seemingly perfect ingredients. This was a plotline that seemed so true and heartfelt, two words that one would be hard pressed to employ about the big romantic twist to the second film. You may have heard there's a wedding. There is. And it's for . . . Stanford and Antony. That's right, two gay characters who always hated each other in the show but now get married because, well, they're both gay. What else do you need to be married?

The difference between how the women's jobs are portrayed in the TV show and the films is perhaps the best example of how low the latter have sunk. In the show, we repeatedly see Miranda working in her office as a partner in a law firm and, yes, the job is hard and time-consuming but she loves it and her success is a badge of pride. Ditto Samantha as a PR. Even Carrie, who works as a newspaper columnist, a job I can personally assure you is not physically taxing, derives real satisfaction from her work, to the point that her willingness to quit it for her Russian boyfriend in the last series is an ominous sign. There is a whole episode about the women's difficulty in accepting Charlotte's decision to quit her job when she marries, and boyfriends who don't take work seriously are seen as immature freeloaders.

Cut to the films. In the first one, not only do we never see Miranda working (because that's obviously less relevant to women's lives than watching Carrie have an orgasm over her new walk-in closet), but her job is the reason for Steve's infidelity, because he wasn't getting enough attention from his wife, who was working to support him. In the second film, guess what? She leaves the law firm! How could she resist after Steve suggested she could "be at home [more] and help out around the house"? Sorry, I think I just burned my fingers while retrieving my bra from the fire.

Then there's the fashion. The women always wore designer clothes in the series, but the movies are little more than two-hour adverts, a point underlined by the fact that Parker is now the chief creative officer of Halston Heritage, a label that features heavily in the second film.

A woman can love fashion without looking and behaving like an international call girl. In fact, the show made this very point in an episode involving an international call girl. Both movies have forgotten this and instead, we are left with Carrie squealing about Dior and Samantha wearing clothes that she seems to have stolen from Joan Collins and the whole thing adds up to Absolutely Fabulous without the fun.

If the movies have killed the Sex and the City dream, then, in retrospect, its death throes could be seen in the last series with its insistence that Carrie had to get together with Mr Big in the end, never mind if it was totally out of character for both of them, never mind if it went against everything the show once said about women not needing to put up with men who make them feel like crap. Weirdly, as the show became more successful, it became more conventional, thereby losing its USP. Bridget Jones – arguably the UK equivalent of SATC – suffered from this problem. The moment in Bridget Jones: The Edge of Reason when Bridget is in jail having a singalong is like the moment in the first SATC film when Carrie agrees to marry Big if he'll build her "a really big closet". Ultimately, both Helen Fielding and Sarah Jessica Parker killed their own franchises, and what's really depressing about this is that it suggests the default position for movies and books about women, for women, is to show them as marriage-obsessed morons.

There are still hours of re-runs of the TV series every night on the Comedy Central channel, and I used to watch them. But the films have ruined them for me. I can hardly make out the smarts and emotions that I used to love because all I can see is the impending conventionalism. Apparently, that's all Parker and King could see, too.

The death of Sex and the City is not just a shame for fans, but for all women with higher expectations of movies about women than a compendium of cliches from the Daily Mail. Carrie, you may have bought a lot of shoes in these movies, but ultimately, you sold out.

• This article was amended on 25 May 2010. The original said that Jennifer Hudson was returning to the south. This has been corrected.