I think, contrary to what many people are saying, that what has really happened is that it has never been easier to hold an opinion about almost anything. Previously you had to at least partly subscribe to some sort of ideology that was somewhat reasoned. Which meant that you were prepared when you met someone who didn't agree with because most ideologies reason around the same things.

Today there are so many source of information that you are never really forced to dive deeper into something. If you see something repeated enough you get a very strong sense of it being true. Many fringe opinions spread without people realizing that they are just that. They aren't used to people disagreeing with them so when people do so strongly they feel alienated.

In regards to Thiel moving, and other VCs praising China, I think that has more to do with people in general becoming more skeptical about SV. Which is a bad thing if you are a VC and are selling "disruption", but probably a good thing for engineers.