Jealousy. A lot of cats never got over Kobe sonning their favorite players on national television while they sat indian style sporting their wrinkled A.I./T-Mac/Vince/Pierce replica jerseys. When Lebron came into the league, they knew he had the best chance to usurp Kobe from his throne, and so they flocked to the "King" in droves.
When Diesel left, they said he'd never win another ring, and attempted to push Wade as the new premier SG. After the 2008 Game 6 debacle vs the Celtics, they said he was done. He followed it up by winning two more rings, a gold medal, and setting Vanessa loose(much to their enjoyment) only to have her come groveling back when she realized how fortunate she was and where exactly her bread was buttered.
Dude won't go away, and he manages to spin any and every fabricated "L" the denizens can think of into a "W", and they hate him for it. They're as much to credit to his success than anything, though. Without them fueling Kobe, he would have never became the paramount of greatness that he did.

Bean transcended every expectation that was bestowed upon him, and is just now showing signs of slowing down. Dude's a living legend, and he's close to hanging 'em up. Regardless of the hate he receives, America isn't ready for that day; they just don't know it yet.