"America's next top model" has only asked for women participants. The criteria for judging male models and female models is different, and the places for them to model (ads, runway shows) is different, so it wouldn't be a fair comparison to have them competing on the same show. Given the opportunity, I think you would find plenty of men wanting to apply for a similar show.
As for the "mathematically better tuned" comment, I've always disliked the arguments that one sex is better suited for anything, especially when talking about the brain. I think socialization has a lot more to do with brain development then sex, and since we've got hundreds of years of gender roles to overcome before we find out for sure, I think we're better off judging individuals, rather then genders.
As for why there aren't more women in startups, or women geeks for that matter, I return to socialization. Bill Gates made it cool to be a nerd for guys, we still don't have a female in that category. A largely successful role model that makes it ok for women to not be entirerly obsessed with their appearence. Maybe when I get my own start up...
I think how you fix the problem is finding other means to make money rather than having users pay. I must admit, if I see a dollar sign on a website, I'm less likely to even try it out. And if I never try it, then I never get hooked, and everyone loses.
I think we're on the verge of a new form of web advertising. One that works, actually makes money, and isn't annoying (like flashing banners). Google's way is a good start, but we need something revolutionary, and once it happens I think the question of whether or not users pay becomes futile.