I'll tell you what it is. Kobe is a dick. People don't like him. He's intense, which is admired, but he's also very good at telling players how to play, embarrassing them publicly, taking over practice, and telling others how to play their position. And his skillset is eroding, so it's not like its a guaranteed ring. Even with Kobe healthy, Lakers are still 4th in the west at best.
think back to that all-star game when lebron passed the ball in the final seconds. Kobe made it a point to approach lebron, already feeling bad about not taking the shot, and went out of his way to belittle him for the cameras, 2 seconds after the buzzer. lebron was smothered and the other man had a better shot. yet because he didn't take a forced shot while completely covered, kobe tried to punk him verbally.
Now, if kobe will do that in a meaningless all-star game, punk lebron when he was already feeling shitty about losing the game last second... imagine the kinda shit he says to teammates and opponents alike, on a nightly basis. He's a dick. He's an amazing player, awesome competitor, and he gives a shit in a world where most players do not. But yeah, he's a dick. Nobody wants to worry about kobe getting in their face every night on the bench when they're up by 15.