The author of the sexist “manifesto” must have lived a very sheltered life if he has managed to be ignorant of the capacity of women to function at the top levels or become leaders in highly technical fields. Among many other flaws in his thinking is that he ignores the fact that overall behavior of both sexes improves in a mixed sex environment, such that creating gender diversity results in an environment where employees spend more of their time doing their jobs and less time bickering. Even if you don’t care about the ethical concerns, increasing productivity should be a no-brainer.
What I have found to be the case working in public and private organizations for over 30 years is that when men who don’t believe in sexist stereotypes or misogynistic behavior say nothing when these things are espoused, the behavior continues. When I was a young, untenured nerd entering the ranks in academia, I was afraid to alienate my powerful male colleagues by telling them this stuff offends me almost as much as it does the women it targets. However, when a fellow who could easily squash my tenure prospects made a sexist comment that could apply to my wife, I realized I was failing her (and every other woman I care about) if I did not stand up to him. When I expressed my disapproval, he stopped doing it in my presence and I received thanks from several of my colleagues. I became much braver, and have found that when I set clear limits on sexist dialog, I earn the respect of most of my male peers.
I do not know what is wrong at Google, but it seems that too few of the men are willing to take a stand, or this would not be happening so much. If the men who do not buy this sexist stuff speak up, the environment will likely improve.