Not so much an evil person, but moreso a fool that fell for conservative and techbro propaganda, John Carmack is insanely smart and intelligent bookwise, but i think his social skills are zilch.

Sandy Petersen is another one i really used to enjoy but the amount of times he’s scammed people out of crowdfunded boardgames has turned me off from anything that has to do with him.

Thankfully John Romero is a great person (afaik) who overcame his ego, probably after Daikatana failed to sell.