Last week David Croft, one of the most successful and talented comedy writers of his generation, died in Portugal. I wonder if he was worried about the euro? It's a nice thought that it's not his problem now. I hope when I'm dying, I remember to reflect on all the anxieties that are soon to become somebody else's problem. The insane terms of my will, for starters.

People have been saying that it's very sad that he died, which it is. But then I'm enough of a woolly liberal to consider "sad death" to be a tautologous phrase. I know that's a controversial view not shared by the Texan penal system and anyone who's ever said: "Death's too good for him!" If you're reading this online and have already started to type: "Oh right, so was it sad that Hitler died, you fascist!?" then by all means keep going, but I reckon I could argue that the specific fact of Hitler's death — taken in isolation from putting a stop to all the killing, which was of course a good outcome because the killing was, to say the least, sad (see above) – was, to a small extent, also sad. It made a lot of people happy of course – but that's sad too. It was a very sad situation.

David Croft's death didn't discontinue a genocide but, even so, I'm not sure it was much sadder than Hitler's. Croft was successful, popular, wealthy and 89. If you start saying deaths like that are a tragedy then you begin to argue that people shouldn't die at all. Which would save a lot of sadness, but things might get a bit crowded. Oh yes, and everyone would go mad at the prospect of eternity stretching before them.

But why have I perversely decided, at this awful time for his family and friends, to get all "Every good thing must come to an end!" about Croft's death, to cite the wider context, to put him in the same sentence as the genocidal maniac whom his greatest work's signature tune lampooned? Isn't this lapse of taste typical of comedians of my generation and the "vomit comedy" that Croft himself bemoaned? Oh, I just had to say something nice about nasty things or nasty about nice ones, having long since confused the sensation of amusing someone with that of causing offence.

Actually I don't think that's why. I think I'm trying to tell myself that it's not the end of the world, because his death has made me feel surprisingly sad. Not because a man I didn't know personally is no longer around – all the comedy shows he wrote, directed and produced remain – but because his death is a sorrowful reminder that the age of television is coming to an end.

Whatever the glories of today's connected multi-channel online catch-up on-demand TV environment, for all that the screens are getting flatter, wider and clearer and the allure of the HBO box-set ever greater, Croft's time was the true golden era of television. It was before choice had robbed it of its ability to unite — when, for better or worse, pretty much every programme that was broadcast got ratings that today would make it a runaway hit.

That gave the medium enormous power. Viewers had few options as to what to watch, so television, like a restaurant with a set menu, could make people try things. It didn't always use that power wisely, sometimes it was racist or inept – I'm thinking of Mind Your Language and Crossroads – but, at its best, it could be mind-broadening and quirky in a way that it seldom is today, and only ever for "niche" channels.

When the ratings success of shows was almost assured, commissioners were under less pressure from bosses or advertisers, fretted less about the public's desires and expectations, and weren't forever in search of an old hit to remake. Consequently viewers were exposed to things they didn't know they'd like, whether they liked it or not, and, surprisingly often, found that they did. It's ironic that being released from the need to attract an audience gave programme-makers a creative freedom, the best results of which attracted huge audiences.

Few people used this freedom more skilfully than Croft. The best of his work is brilliant and, while some shows were patchy or went on for too many series, they were all interesting. They had situations at the heart of them that were funny and specific: an old-fashioned department store, a café in Nazi-occupied France, a Royal Artillery concert party in British Burma and, most successfully, a Home Guard platoon in a seaside town.

This very specificity would scare off many channels today as they'd fear that these small worlds wouldn't be of interest to a broad audience. Yet these shows were mainstream hits. No one would ever tell a focus group that they were crying out for a comedy about the desires and jealousies of people running a holiday camp in 1960, but it turned out that millions were.

The mainstream sitcom hit is the holy grail of television, in a world where people actually remember the holy grail being there on a shelf but then one day it went missing during an episode of The Brittas Empire. We all believe that it's still possible for a comedy show to bring people together; that it doesn't always have to be a cult thing, over which a particular section of the audience feels ownership but which the wider public finds offensive, boring or incomprehensible.

Illustration: David Foldvari

My hunch is that, if the grail is rediscoverable, it'll be where David Croft left it – in shows that are individual and peculiar but that broadcasters find the nerve to market to a wide audience rather than pitching to a niche.

Dad's Army is still on terrestrial television. That odd, very historically specific scenario has amused and touched a mainstream audience for more than 40 years. When it started, many Home Guardsmen were still alive. Now wartime children are in their dotage. Its writers, Croft and Jimmy Perry, used that small-scale setting to be funny about enormous subjects — class envy, war, ageing, mortality, fascism and even, in Sergeant Wilson's relationship with Pike's mother, sexual shame – and to create intriguing characters whom millions loved.

No art form can do that as well as sitcoms, and even they seldom manage it. I'm sad to hear of the passing of a man who made it look easy.