From my perspective, it's the culture that develops around the "liberal politics" that is the issue. I don't think anyone is complaining about "getting heat for political views". I mean that's just politics. What I've experienced at various companies, though, is that the culture becomes infected with the politics to a point where it impacts the way companies operate and even individual employees' ability to perform their job at a capacity that can produce value. This is where I think it crosses the line. Effectively, companies or individuals end up handicapped by the political agenda. And that makes zero sense rationally for the business. It's literally not their business to be in politics.
I'm hesitant to share anecdotes so I'll keep them fuzzy, but a few things I've seen are along the lines of places removing a comedic joke item because it /might/ give a newcomer the impression that the place "normalizes fascism" (rationale was fear someone wouldn't understand it's a joke and thus let's err on the side of keeping the space sterile), and hiring/comp policies designed around explicitly not paying men more than woman for the same role (everyone's the same role when your company doesn't have roles...) regardless of experience, performance, market, etc. at the expense of acquiring or retaining outstanding talent. And look what happened at Google...
It all comes from good intentions, but IMO it really just misses the mark and reduces an otherwise complex and human landscape to arbitrary statistics and n=1 anecdotes. There is very little intellectual rigor, or proven methodology and a lot of pandering to the political atmosphere (and this happens at places juggling millions of dollars of investor capital). On top of that, I don't understand why the office needs to be the place to explore these issues. If there are objectively systemic issues and discrepancies between e.g. genders in the US today that need correction, then we need to solve those with government policy and social activism. And if our society and our system of government does not respond, perhaps you just have to grow up realize that despite your self-endowed intellectual infallibility, some other people disagree and you might be barking up the wrong tree. Or, don't concede and keep fighting for justice, but don't bring it to work because you're too impatient or lack the perseverance to see your issue through at local, state, and national levels.
So even if other areas might have (for the sake of the argument), on average, more jerks that just don't get it or have a few things to learn about being inclusive and respectful in the way they conduct their daily lives, people don't build operational business policies around solving the perceived problems or shortcomings (not saying HR departments can't lay ground rules, but I'm talking about operational strategies). And that's the difference between an office in SF and an office in NYC or Boston, or Austin, etc.
I would not be surprised if the fact that people find some of Thiel's politics to be unfavorable is impacting his ability to function professionally in the Bay Area. When people's professional livelihood is at steak, of course they will gravitate towards communities where they are not otherwise encumbered. In the case of Thiel, money seems less of an issue, so I suspect he's also making a social statement about the state of affairs down by the bay. Celebrate or listen, but I hope you choose to listen because talent and money are all SV has got going for it, and if those things leave you can kiss the glory days goodbye.
/2cents