Here's my view on this as a young female computer nerd: even with all the negative stereotypes attached to the male computer nerd, the fact remains that (a) he is typically male, and (b) he is not the only one of his ilk.
Let's consider the perfectly realistic scenario where society has only just recently realized that women are good for more than making sandwiches and childbearing, and can are capable of doing professional jobs as well as any man. Thanks, society! But since this change just happened recently, it is not unreasonable for there to still be fields that are male-dominated, despite the fact that women are just as able to work successfully in these fields. This is what gives us (a).
However, now that the floodgates have opened, women would really like to get into tech! But first, there's everything that cheez mentioned -- society's subtle socialization of women into their proper gender role. Boys are expected to tinker with and possibly break their toys, girls should be combing doll hair. And later, the boys who are nerds almost always find a nerd clique...which is almost entirely comprised of other boys. And the girl who wants to bond with somebody over her nerddom? All the boys are scared of her, for she is GIRL, a separate and incomprehensible breed from BOY. And there's condition (b).
Personal anecdote time: all of my friends (which is stretching it) in high school were guys because the other girls at my school thought computers and programming and video games were "a guy thing". and even among this group, I only had one who truly respected me (who brought me into the circle in the first place) -- to the rest, I was the token female to be awkward around and bounce sexist jokes off of. During that time, I was a huge tomboy and a huge jerk -- not because I don't like doing typically femme-y things, like wearing makeup and dresses, but because I felt like I'd be more accepted if I wore guy clothes and made dick jokes and, yes, sometimes even objectified women and acted homophobic (but only for men, because lesbians are hot, har har) for the sake of humor. Even being more "guy-like", though, never really earned me any respect -- even if I laughed at their jokes about "dumb bitches" and made my own, the fact remained that I was still born without a penis and could therefore never really relate. It was only after I got to college that I was able to recognize my disgusting attitude for what it was and realize that it was possible to be both femme and a CS major, though that would have earned me no love from most of my HS "friends".
tldr, men do have to overcome the barrier of being socialized to like sports and fast cars and what-have-you, but once they do, they've at least found more of their kind. Women, on the other hand, face that barrier two-fold -- both from outside and within the community, and that really, really sucks.
But I'm so glad that this conversation is happening, because I really do think that making the tech industry more welcoming to women is important -- and if it turns out that you're right, that at the end of the day more boys and few girls go into tech anyway, at least we're still a kinder, better, more accepting community. What do we have to lose from that?