If somebody has an, honest reasonably considered question that they would like to raise after having done at least a modest amount of work to answer themselves, sure, let's talk about it.

But most speech isn't like that. It's persuasion, advocacy, negoiation, action. Indeed, the Google manifestbro was quite clearly advocacy. It wasn't a question. It was a ten-page screed meant to convince. In specific, to convince people to act differently. Those actions will have real-world consequences. It is entirely unshocking that people who would be harmed by those consequences will vigorously object.

Nobody is talking about censorship here: https://xkcd.com/1357/

We are talking about one person saying something and then other people exercising their freedom of speech and freedom of association in response. The guy certainly has the right to claim that women are biologically inferior. But his coworkers have the right to tell him that a) he's wrong, and b) he's an asshole. And Google has the right to say, "Thanks for your service; see you later."

That's freedom. If you don't like it, well, you have the right to say so.