I think people still respect Couture, both in the sense of his legacy and his ability. They just don't think he'll ever be relevant in the title picture again.
Anderson gets hated so much, because he's so good. People ONLY expect greatness from him, anything less and he's being a douchebag somehow. And yeah, some people I know, myself included, aren't comfortable doing something, especially publicly, unless they know they will be competent at it. I understand his timidity to speak english.
Bisping is a nonce, but he is a talented fighter with some decent wins under his belt. Most of his fights are pretty exciting and he has fairly well rounded game.
People who were bullied in school hate Brock. Traditional 'martial arts fans' hate Brock.
Douchebag extroverts hate GSP.
While it is slowly dying away, Dan Hardy seem to rub people the wrong way even though he seems to be smart and a pretty decent guy. Yeah, he thinks he's tougher than he is, but most fighter's do