Here's a lovely old granny in a pale-blue coat with her silver hair all curled and set.

And here's that lovely old granny spitting nastiness about another woman. "She's a dirty great fat lump of lard," she shouts, her lips curled back so we can see her teeth. And here's another granny talking about the same woman, with the same venom. "She wants shooting," she says. "Because she's dirty. DIRTY."

What on earth can this be? What can transform women in this way? What turns grannies into monsters? Or am I being sexist? Or sneerily middle-class? That's the problem with wrestling. For some reason – and I have no idea what it is – certain women loved its play-acted violence and its blood, but it's hard to criticise them, or wrestling, without appearing snooty.

One interviewee in Timeshift: Wrestling's Golden Age (BBC Four, Thursday, 9pm) says it was this kind of middle-class snootiness that killed wrestling off as a TV sport in the 1980s. Television producers decided audiences did not need fat ex-miners in Lycra even though fat ex-miners in Lycra seemed to make lots of people happy at four o'clock every Saturday afternoon.

And he's half-right, that wrestler, because there were two reasons wrestling disappeared from television. One was, indeed, the middle-class factor – essentially, TV producers in Margaret Thatcher's 1980s began to see that the working-class audience, the non-aspirational audience, weren't the kind that would attract nice advertisers. They didn't need them so they got rid of them.

But the documentary makes something else clear, and it is just as important: wrestling killed itself. The whole thing began as an entertainment in the music halls, with fighters rolling a mat out on the stage. Then, in the 1930s, a wrestler called Norman Morrell rebranded it a sport and brought it into the mainstream. By the 1960s, it was a television hit. By the 1970s and 1980s, 16 million people were watching. But we learned in the Timeshift doc that even in the early days of wrestling's television success, the promoters were dictating who should win fights because they needed a soap-opera narrative with characters. Most of the wrestlers, though, maintain they were taking real knocks, and the clips of wrestlers with their faces busted open would seem to back that up.

By the middle 1980s, however, wrestling had been belly-butted into a different era entirely – it had been refined so much that there was more acting than sport, and not even very good acting. It was pantomime, with goodies such as Big Daddy, and baddies like Giant Haystacks or Klondyke Kate, the woman at the receiving end of those venomous grannies. TV gave up on it.

And despite those accusations of middle-class sneering, that was the right thing to do. Not because of the faces of those grannies transformed from sweet to hate, although they were disturbing. Rather, wrestling had to go for another reason. The mission of culture – low and high – should be to become more interesting, more exciting and more inventive. But wrestling had become unsophisticated, a circus act. It wasn't a sport, it was bad art. And it didn't die, it was put down – for purely artistic reasons.