Why do Americans hail Fischer when he was anti-American and idolized Hitler? Whenever I talk chess legends with some Americans I know, they love to hype up Fischer and call him the greatest ever and what not.

While I appreciate Fischer's talent for chess, and he is certainly one of my top 5 players as well, I do not understand this love that Americans in particular have for Fischer, who, as a person, was as anti-American as it gets, and in general a vile human being.

Didn't he profess his support for Nazi Germany? So why do Americans show this bias for a person that actually hated Americans?
Fischer had psychological problems. He was American and hated the US. He was jewish and hated Jews. He was clearly paranoid from a pretty early age, but it got much worse after he stopped playing. 

It is hard to see an antisemitic Jew as evil. I think it is more reasonable to feel some empathy for his mental problems. And we can all count ourselves lucky that his mental health held up long enough for him to create a large number of chess masterpieces.