Inadvertently, Sherlock proved that the BBC still cannot recognise a good drama when it is in front of its nose. It made just three episodes and broadcast them in the dog days of summer. It messed about with the transmission time — 9pm one week, 8.30pm the next — as it always does with unloved programmes. Only when Sherlock was a critical and popular triumph did it announce it would commission more episodes.

A friend with ambitions to break into the media discovered how unimaginative today's executives were when he went to a training session for aspiring producers. He swiftly became disillusioned after he bumped into Jay Hunt, the controller of BBC1. She told him that her station was reluctant to commission anything that did not have a celebrity in it. Ms Hunt may know what works for light entertainment, but she does not understand drama. At the same time as the BBC was running Sherlock, it was showing The Deep. Minnie Driver was the female lead, but she couldn't breathe life into a dead script. Running alongside it was Mistresses, a bloodless Aga saga which even the presence of the divine Joanna Lumley could not save.

Gore Vidal's assault on the auteur theory of cinema is a help here. Contrary to the French theorists of the 1960s, he pointed out that the films of the Hollywood golden age were not the work of directors, whom the French took to be creative geniuses on a par with the greatest novelists and artists. The studios handed a director a script and heaven help if he did not follow it to the letter. The best director in the world could not turn a bad script into a good film, said Vidal, with the authority of a man who had worked at MGM with Dorothy Parker and William Faulkner.

The same applies to stars. Benedict Cumberbatch (Holmes) and Martin Freeman (Watson) were hardly unknowns before Sherlock. But they were not celebrities — although I am sure they are now. One argument I hear a lot is that British television companies cannot compete with the Americans because they lack the financial base of a mass audience and so cannot afford the talent. Its proponents do not understand that the producers of a television drama do not need to spend a fortune on hiring stars. When they come up with a new idea, they can look in the large pool of underused acting talent, instead. As the Americans know, new television drama makes stars, but it does not need them. It needs writers.

I may be being unfair in criticising Jay Hunt. The internal market at the BBC means in effect that one man has the ultimate authority to approve ideas, which he then offers to the channel controllers. His name is Ben Stephenson, the head of drama commissioning. Even if had the discernment of a Medici prince — and if he does he keeps it well hidden — he is far too powerful. Equally, it is certainly unfair to concentrate on the BBC. Sky is now the richest broadcaster in Britain. But because Rupert Murdoch buys business favours from Labour and Tory governments by offering them the support of the Sun, venal politicians have exempted Sky from the regulations governing public-service broadcasting. As a result, Sky produces no drama worth mentioning.

Whichever way you look, however, you always see the poverty of the ambition of the current generation of media managers. Good television, like any other good art form, needs money. But more important than money is the will to make good television and in Britain that will isn't there.