Also he is a ~2200 ELO-rated chess player. That alone would make the baseline IQ and ability to think through logic, analytical thinking, calculation skills and stratetic planning beyond most HN users, even though in a small domain of Chess; I'd wager more broadly.

https://ratings.fide.com/profile/2022389

Personally, I find his thinking savagely brutally straight to the point and cuts through cultural rust we've built up in our thinking process. It is fascinating, I don't agree with him on a lot of things but I admit, he is interesting.