I'm sorry but I can't find where he said this. I'm finding it confusing and suspicious that the objections to Palantir & Alex Karp are all so vague and seem to lack the rigour typically required of assertions made here on YN. Usually if you declare something like someone "argues clearly for authoritarianism," you're expected to link to a source of this claim.
People keep telling me here it's so obvious Palantir is bad I shouldn't require any specific evidence and I'm stupid if I don't see it; I'm only reminded of the emperors new cloths.
Are you going to suggest that Thiel's role as chairman of Palantir is ceremonial and he's just there to make the tea and arrange the flowers?
The point is that democracies tend to want to erode liberties. Take the age gating bills floating around as an example.
The solution Thiel proposes is not eliminating democracy. It's building technology that governments cannot easily control. Cryptocurrency is one good example of this.