People should get fired for not doing their jobs -- not for writing what they think. And I also want to say that before you blame "the Left" for Google's behavior... Had he been fired in "Socialist Europe," the firing would have been declared against the law and Google would have had to pay a hefty fine.
I can add why I'm so sure he wouldn't have been fired. In most (many?) European countries, you can be fired for only(!) two reasons; misconduct and labor shortage. Misconduct must be specifically related to your job performance. Like, a train conductor that always oversleeps or a cock who can't boil eggs. Something quite a bit more obvious than claiming gender differences between men and women. Labor shortage is if there is not enough work to do and then the company can let go of the surplus personnel.
The walkthrough of the US laws, that tptacek provides, shows that they are completely different and much less employee friendly.