Aren't we missing something here? Med schools try to have 50/50 gender split in their incoming classes. Heck, patients certainly 50/50. Med schools don't even want gender diversity, they want gender parity. CS departments can't fathom such a thing. And while employers like diversity, they don't need parity. Startups need skills, not stats, so it's not a priority for them either. I'm not saying females are not on par with their male counterparts in s/w and medicine by any means. But at least their are role models and courtship in medicine.
I think a lot of CS departments would be happy to aim at 50/50 gender parity, if their application pipeline were anywhere near close enough to support it. When applicant ratios are in the range of 90% male, it's very hard to get more than 20-30% women in the incoming class, even if you really go out of your way to aim at gender balance.
It took med schools a few decades too, over which they first removed overt barriers (like "medicine isn't for women" attitudes among faculty), then successfully convinced more women to apply, and then finally accepted many of those applying women. CS's troubles are complex, but I think one of the stickiest ones is that interest/disinterest in studying CS seems to develop around high-school (same as studying math), so the imbalance somehow has to be addressed at the pre-university level. Med-school doesn't seem to have the same differentiate-by-age-15 aspect.
Gender parity is more significant for medicine as there are a great many patients who have trouble working with a doctor of a particular gender. It's not always same-gender pref either - I know of two women who prefer male gynaecologists because they're less rough when examining.
Given the importance of medicine to leading a happy life, it's important to get as much information out of patients as possible - so it's in the interest of the industry to make sure that the client-facing staff have plenty of both genders.
It's much less important in programming as users and programmers rarely interact. Was Firefox written mostly by men or by women? It doesn't matter to me as I don't interact with them in order to use the service Firefox offers.
