That's possible. It's also possible, as Thiel says, that people shy away from unpopular truths out of conformity bias. Which is the bigger bias?

In Thiel's view, (and mine), the chief problem is not that people are overconfidently proposing answers to that question. The chief problem is that people have no answers at all to that question, and can't think of any ways to generate them. You are right that it's a hard question, because you can be mistaken, and reversed stupidity is not truth, and so on. But it's not an impossible one.