Jodie Whittaker: what an inspired choice for the new Doctor. Not only is she a very fine actress, whether she’s playing stricken with grief, as she did in Broadchurch, or a comedically exasperated trainee nurse stressed out by aliens and chavs in the wonderful little film Attack the Block. She also exudes that quality every good Doctor needs: the everyman touch. Or everyperson touch. The sense that while this creature might be a Time Lord with two hearts and a police-box time machine, he — now she — is nonetheless like us. Special but connectable. Otherworldly but worldly. Whittaker can do that. I think she’ll be brilliant.

But my joy at seeing an actress I admire land a coveted role has been dampened by the crazy reaction to the news. You’d be forgiven for thinking that making the thirteenth Doctor a woman is on a par with women getting the vote. Twitter has evaporated into a paroxysm of joy. This will transform life for the female of the species, apparently. We cannot underestimate ‘how important a female Doctor is’, says the Huffington Post. This casting helps ‘break the glass ceiling’, says a self-congratulatory BBC (inflaming suspicion that it chose Whittaker because she’s a woman rather than because she’s good at her job). Whittaker will inject ‘girl power [into] space and time’, says one observer.

Writing in the Guardian, the sixth Doctor, Colin Baker, says Whittaker’s arrival reverses ‘the exclusion of [the female] gender from the Tardis’ — as if not having a female Doctor was an act of misogynistic repression rather than just a quirk of TV history. A writer for Variety says women have ‘won a victory’. She hails the casting of Whittaker because it ‘sends a message’ — that women and girls will no longer be ‘shut out of seeing themselves on screen in plum roles’. Women don’t land plum roles? Is that true? Tweeting, weeping liberals claim a female Doctor will have a revolutionary impact on their daughters’ sense of self-worth. I don’t know what I find more dubious: the notion that teen girls watch Doctor Who or that a Whittaker Time Lord will boost feminine self-esteem across the land.

The overblown response to the thirteenth Doctor confirms how stupid, and worse, identity politics is. It confirms how obsessed the virtual left is with cultural messaging. This flimsy group gabs about imagery far more than it does matters of substance. Gone are the old cries for full employment or marches for jobs, and in their place we have an irritating, myopic, often self-serving demand for greater diversity on TV, radio, in magazines. We need a female Doctor, a black James Bond, more female voices on the Today programme, plumper mannequins in shops, traffic lights that are gay-friendly (seriously), in order to make sections of the populace feel less depressed, apparently.

There’s something deeply conservative, distinctly un-radical, in this obsession with the surface of things. It leaves society itself unchanged. Sticking with women: after yesterday’s announcement, vast numbers of women will still struggle to make ends meet, and having a female Time Lord will make not one, solitary, infinitesimal iota of difference to that. Whittaker’s turn as the Doctor might boost the happiness of teenage daughters of Guardianistas — allegedly — but it will do nothing to improve the esteem or lot of working women or hard-up new mums or white working-class girls who are less likely than middle-class girls to stay in education up to A-Level. Identity politics polishes the exterior of society while leaving its deeper problems untouched. It’s such a con.

The frenzy over the female Time Lord also shows how patronising identity politics is. How insulting to suggest that women needed the thirteenth Doctor to be female, or that trans people will crumble if they hear the phrase ‘Ladies and gentlemen’ on the Tube, or that black people need to see people like themselves in a story if they’re really going to connect with it. The idea is that ordinary people are tragically fragile, going about in a permanent state of self-doubt, and so we must have our esteem massaged by cultural overlords. ‘You ARE valuable!’, these powerful people must tell us. It’s anti-universal too. The notion that black people better understand art featuring black people, or that girls will get more from stories written by women, as Caitlin Moran suggests, grates horribly against the humanist idea that what unites us — our aspirations, our autonomy, our capacity for love and greatness — is far more important than accidental differences in gender and pigmentation.

What’s really off in the celebration of the new Doctor is that it makes the whole thing reek of tokenism. It implies that the most important thing about Whittaker is her gender. We’re actively invited to judge her by her gender. We should refuse. We should judge her by her performance alone, and by how well or differently she inhabits this most British of TV characters. I predict she will do it well, not because she’s a woman, but because she’s a very talented person.