I note no woman has posted on this threas since #57, and that's one of only two comments by women on this page.
I'm not a gamer. I got distracted and lost interest in computer games at around the time that mainstream games were starting to develop decent graphics and meaningful character-driven plots. Suffering from horrendous travel-sickness in first-person 3D environments doesn't help.
But I'm a geek, and I know a lot of gamers. Some of them are women, some of them are LGBT. Gender stereotypes about the type of games the women prefer to play are probably accurate - while they'll dabble in most things, it's the role-playing type games that seem to keep their interest (I'll handwave over Cow Clicker and the like). From second-hand reports, about the only thing more insidious than the sexism in online gaming communities is the homophobia, to the point that it makes people weary of games they'd otherwise enjoy (yes, even virtual worlds where the possibility of same-sex relationships have been conspicuously overlooked by developers). Gratuitous boobs are an occupational hazard of marketing pressure on art departments, and generally regarded as humorous, even by the straight males. I suppose you need that attitude, or the maturity of a homophobic 12 year old, to put up with it.
It's all pretty sucky, really.
As for sci-fi, in which I have a much greater interest, it's again about marketing. Which disproportionately affects film and television. It means that things are more likely to be commissioned if they have obvious appeal to a young (which often means children and teenagers, to the detriment of the story) predominately male demographic. It means that sci-fi and fantasy based television series are inherently less valuable to the advertisers (it's much easier to sell things to young, reasonably well-off women than it is to nerds), and it means that good series get axed because a target demographic of people who are technically capable and watch TV on their own terms don't make for good ratings.
With the notable exception of the occasional fantasy epic, churning out violent action films in a sci-fi/fantasy setting, or good quality film versions of classic comics storylines (aimed squarely at younger teens) is where the money is. Do it well, and you'll get the target demographic, plus all the hardcore fans who'll watch it even if it's terrible. And they'll keep coming back, regardless of how much Alien no longer makes sense, or that Pepper Potts gets developed and then screwed over time and again.
Books and comics remain where the good stuff is. Marketing works differently, there. As does the "fake geek girl" phenomenon...