Because he was so good, he could say things about the game that were controversial, but deep down a lot of patzers knew that what he was saying was right.
Sure, one's source of enjoyment from chess varies between players, but what both Scott McCloud and Fischer were pointing out is that winning a game of chess makes you feel wonderful, and losing one makes you feel bad.
I think virtually every chess player would be familiar with those feelings, and would concede that "crushing the other guy's ego" (or its corollary "not having my ego crushed") has a little bit to do with it.
Whether you are playing Spassky for the World Championship or a game of blitz with a friend, the emotions are the same.