It's not hard to like the character, far from it. What's hard is to not get many titles while 20% of DC's roster is Bat titles. Hard to be a fan of something everyone else hates. Hard watching him shrug off explosives but fall from a punch from Batman. Hard to not get much additional media like games or cartoons, especially compared to Batman who gets new games and cartoons every year.
I must say, Supes may be an a-lister, but it doesn't feel that way anymore.