Comparing Anderson Silva, Jon Jones and GSP.. honestly i think GSP is the nicest guy from those three, he is seemingly the least offesnive and egotistical.
Saying that i'm a big fan of all three but i can understand why some people don't like them.. Anderson Silva is almost perfect, he rarely says anything wrong although has shown some unprofessionalism when facing Brazilian opponents, seemingly not wanting to stop them.
Jon Jones is cocky, he would ofcourse say he's just confident but he is a bit cocky and that for me is fine, afterall he is possibly the most dangerous man on the planet, but some people are going to hate.
GSP, my overriding thoughts on GSP is watching the countdown shows where the guy almost has nervous breakdowns before hsi fights, disects his own game into a pile of shit and generally worries himself to death - yet despite this is one of the best in the game. We're all different but i must admit i like that this guy has a real ego, he is nervous he is worried, like a normal person etc yet he is still the world champion.
You do probably have some factors like racism playing into the dilike for AS and JJ, let's be frank this is an American sport and some of the spectators/fans are going to be racist sadly. No doubt Griffin/Franklin/Hughes win extra points with the likes of Oldfan, Sideways and Rusty etc.