This isn't a modern thing, either. I've never seen anyone claim Brendan Eich didn't have a right to donate to his cause, it's just that he donated to the wrong cause, at least in they eyes of the media and the Twitterverse, of all places. Here, we're seeing it again with Thiel: he has the right to donate to whatever cause he wants, but we criticize him for donating to the wrong causes.
For all the talk of cultural and gender diversity, political diversity is shunned. This is far more pernicious than criticizing a startup because they haven't hired enough women or PoC