You're having a laugh, aren't you?

Spike Milligan wrote gags for Goons between pulling pints. He wouldn't get away with that today.

British comedy: jokes about the railways, the NHS and the incompetence of the Labour government. The same smug people making them, week after week.

That was certainly how it seemed in 1950, when Spike Milligan decided he could do better. A jazz guitarist with a sideline in funny stories about the war, he decided he would get into the BBC. He took a job as a barman in a pub whose landlord wrote jokes for a radio comedian. Between pulling pints, Spike cracked jokes, which the landlord wrote down. The jokes turned into scripts, and soon a BBC producer gave the barman, his landlord and a couple of friends their own show. It was The Goons. It lasted 13 years, changed British humour for ever, and couldn't happen now. The last radio show taking unsolicited jokes, News Huddlines, died in January. Once it was possible to get a broadcasting project under way while you were still enthusiastic. Take Monty Python's Flying Circus; only 12 days after their first meeting, in May 1969, the writers won a 13-part BBC2 series. Like Milligan's career, it happened because the BBC trusted its own people: in this case Barry Took, a staff producer.

Today, ITV has all but abandoned comedy, but the BBC has not lost faith. This week it launches a clutch of new comedies and near-comedies. There's a comedy-drama, Rescue Me, starring Sally Phillips as a magazine journalist, a comedy-documentary-travel show called Billy Connolly's World Tour of England, Ireland and Wales, and a sitcom, All About Me, with Jasper Carrott and Meera Syal.

Phillips is nicely turned out, and her show is attractively shot. But it won't crack you up. Of course – let's make the excuse for it – it's not really meant to. But that doesn't work for All About Me. All bright lighting and "cute" children trading quips, it made the studio audience very happy; perhaps they don't get out much. Jasper Carrott, a real entertainer, becomes a one-note Brummagem Victor Meldrew. Meera Syal looks miserable. It has some good lines, and many, many stinkers.

But this show, too, has an excuse. It's "brave" and "inclusive". Apart from featuring a mixed-race second family, it has sitcom's first seriously disabled character: one of Meera's children is in a wheelchair. He never speaks, except in a witty-yet-challenging voiceover. Could they be so cynical as to use this taboo-breaking to deflect criticism? If so, it won't work. This show is "brave", "inclusive", and useless.

The secret of comedy is not timing. It's confidence, and confidence permits originality. And with more channels and less money, confidence is in short supply in broadcasting. Instead, there is fear.

The big problem is television management's obsession with stars. "They genuinely don't understand that writing comedy is a specialised and difficult job," says a former BBC man. "They have a contempt for writing and an adoration of the on-screen talent." He recently took a script to one of the top decision-makers in British television, only for her to explain that she never looked at scripts: only cast-lists.

"There's a ratings obsession," says Dave Cohen, a writer on several of the comedy panel games that have largely replaced mainstream comedy. "Ratings, scheduling, market share, focus groups, all that management stuff."

Comedy is expensive, perhaps too expensive for us, unlike the Americans who pump money into pilots. In Britain the emphasis is on "value for money". Some writers now have to attend "read-throughs", even before a script has been commissioned, with actors hired to perform "an idea of the script" in front of a management team. "The problem is always the money," says Cohen. "The fact is that sitcoms are like movies; you have to make a lot of bad ones to make one good one. We are not making enough."

The launches of ITV, BBC2 and C4 all boosted the comedy world. But the new channels have split the available funds rather than bringing in more.

In the old days, BBC executives never interfered. Apart from the producer, no one ever saw scripts, recordings or preview tapes of Monty Python. The Head of Light Entertainment, Tom Sloan, detested the show. But he still put it on. The man who discovered Milligan, Dennis Main Wilson, died in 1997. Once, a BBC scene-shifter named John Sullivan approached him, bearing a script he had written for something called Citizen Smith. "I have heard you're a chap who is willing to give unknowns a chance," he said. He was right: Main Wilson was like that. For the sake of comedy, let's hope others are like that too.