My kids are half-Chinese. If one of my coworkers said "these half-breed children are polluting our race", I'm pretty sure I'd shy away from working with them. Damore basically implied that Google lowers the bar for female engineers (which it does not), and therefore immediately cast doubt on the quality and merit of his female coworkers.
If I was a woman, I might decide I don't want to work with someone who feels I'm not really supposed to be there.
Damore didn't say or imply what you're claiming either. I wonder how carefully you read what he wrote, if at all. He talked about interest at the population level. He didn't claim female Googlers weren't as good as male Googlers. That was a strawman thrown about by people who couldn't argue with his actual points and so preferred to argue with something else.
So - lots of assumptions on your part, all wrong. Not the type of data driven analysis I remember Google exalting, back in the day.
I previously worked at IBM and Oracle for years and I can tell you, that kind of behavior is exponentially worse, complete with engineered backstabbing and deliberate sabotage against coworkes. So if that's Kindergarten behavior, Google is college by comparison.