You're right, this could be more cultural than biological, or some mixture. There's definitely something going on. First consider the lack of women in STEM fields combined with the fact that more women than men are going to universities and earning degrees. Women just simply aren't choosing STEM as their choice of study for a career path, whatever the reason might be. 20 years ago a big push started with engaging young girls in education and STEM topics.
If we look more closely at the STEM stuff, there's been a decline of women wanting to get STEM degrees, not more women, in that same 20 year push. Women are largely choosing other areas in STEM.
Maybe it's cultural, maybe it's biological, maybe it's both. The big push that started 20 years ago is an effort to balance out the cultural aspect. Either the efforts, as far as tech go, have horribly failed, or, women have a predisposition against tech.
It's incredibly difficult to get something close to a 50/50 split in an industry, if that's the companies stated goal, when the available pool of candidates just aren't there.
what he did was embarrass his employer
Huh? What he did wasn't embarrassing to his employer! The people who leaked it were out to embarrass Google to get him in trouble. The whole memo stayed inside of Google until then, for a whole fucking month.
assert at least some portion of his female coworkers were unworthy
Citation fucking needed.
We are not a clone.