> For me, I'm not sure how productive all this gender hand-wringing really is.
It's potentially very productive. The culture of CS, "judgmental introversion" as you put it, is not anything intrinsic to CS. Indeed, software engineering is a profession that demands a high level of communication and cooperation. The "lone hacker" stereotype is in my opinion quite the opposite of the kind of people you want in software engineering (or engineering generally).
One of the things the whole "affirmative action" debate ignores, on both sides, is that cultures are self-perpetuating, but affirmative action can move cultures to new, self-sustaining equillibria. The lack of women is by itself something that creates a barrier to entry for women, and once the ratio is corrected through affirmative means, the new equilibrium becomes self-perpetuating.
I'll use as an example the profession of accounting. Accounting, like CS, has a perception of being introverted and nerdy. Yet, 45-50% of the employees at Big 4 accounting firms are women. Across the field, 20% of all partners are women, and more importantly, 43% of new partners are women (http://suite101.com/article/accounting-is-becoming-a-womans-...). But there is no affirmative action for women in accountancy. It's not easier to get a job at PWC or E&Y as a woman. The affirmative action is no longer necessary--because women aren't self-selecting out of the profession, firms don't need to dip down to get equally qualified candidates.
The legal field saw a similar shift as a result of affirmative action for women. In a field that used to be an "old boy's club" half of new associates are women and 30% of new partners are women (http://www.bizjournals.com/triangle/blog/2012/01/report-30-o...). But at least at the associate level there is no affirmative action any longer--the new equilibrium is self-perpetuating. It's self-perpetuating because balancing the gender ratio changed the culture in a way that made the profession attractive to women. And you know what? The culture is better. It's modern and professional. There is nothing intrinsic about smoking and dirty jokes that made you better at the practice of law, and frankly there is nothing intrinsic about playing WoW in your spare time that makes you better at programming.
So your dichotomy about "meritocracy" is short-sighted. There is nothing "meritocratic" about indulging male culture to keep a field male-dominated. Indeed, that's anti-meritocratic. Affirmative action, ironically, by balancing gender ratios can move the culture in a direction where you can have true meritocracy--where women don't self-select out of a profession because they don't want to be the minority, and where in the long run you don't have to dip down to get qualified women because the qualified women aren't turned away by the male-dominated culture.