Tim Cook is now the most powerful gay man in the world. This is newsworthy, no? But you won’t find it reported in any legacy/mainstream outlet. And when the FT‘s Tim Bradshaw did no more than broach the subject in a single tweet, he instantly found himself fielding a barrage of responses criticizing him from so much as mentioning the subject. Similarly, when Gawker first reported Cook’s sexuality in January, MacDailyNews called their actions “petty, vindictive, and just plain sad.”

But surely this is something we can and should be celebrating, if only in the name of diversity — that a company which by some measures the largest and most important in the world is now being run by a gay man. Certainly when it comes to gay role models, Cook is great: he’s the boring systems-and-processes guy, not the flashy design guru, and as such he cuts sharply against stereotype. He’s like Barney Frank in that sense: a super-smart, powerful and non-effeminate man who shows that being gay is no obstacle to any career you might want.

One of the issues here is that most news outlets cover Cook as part of their Apple story, and Cook’s sexuality is irrelevant to his role at Apple. And so the other story — the fact that the ranks of big-company CEOs have just become significantly more diverse — is being overlooked and ignored. And that’s bad for the gay and lesbian community more broadly.

The institution of the closet is one of fear — one where people would rather be ignored than noticed, because they fear the negative repercussions of being known to be gay. It’s an institution which Cook, like any gay man born in 1960, knows at first hand. But now the risk of being ignored is bigger in the other direction: if the world can’t see gay men and women in all their true diversity, if the only homosexuals they know of are the flamboyant ones on TV, then that only serves to perpetuate stereotypes.

As the Apple story moves away from being about Steve Jobs and becomes much more about Tim Cook, we’re going to see a lot of coverage of Cook, the man. He is, after all, not just one of the most powerful gay men in the world; he’s one of the most powerful people in the world, period. The first instinct of many journalists writing about Cook will be to ignore the issue of his sexuality. It’s not germane to his job, they’re only writing about him because of the job he holds, and therefore they shouldn’t write about it.

On top of that, Cook is not exactly open about his sexuality, and Apple has never said anything about it. Cook’s formative years, professionally speaking, were the 12 years he spent at IBM between 1982 and 1994 — and at that company, in those days, coming out was contraindicated from a career-development perspective. Mike Fuller, a gay VP at IBM, told The Advocate in 2001 that he knew “IBM employees who worked for the company in the 1980s who told me they left IBM because they weren’t comfortable coming out at work”; this comes as little surprise. After all, the years that Cook spent at straight-laced IBM coincided with the height of the AIDS panic, when people were worried about sharing toilet seats with homosexuals. It would be hard to come out at any company in that kind of atmosphere.

But thankfully we’ve moved a very long way from those days. Homosexuality is no longer something shameful, to be coy or secretive about — especially not when you’ve risen to the very top of your profession. In fact, it’s incumbent upon a public-company CEO not to be in the closet.

Felix Salmon is an Audit contributor. He's also the finance blogger for Reuters; this post can also be found at Reuters.com.