Dude, it's time to move on from that. It's been nearly two years. LeBron has admitted that he went about it the wrong way, and the Heat organization has said they regret the introduction they made after signing Bosh and LeBron as well. The Decision is NOTHING compared to what other players have done off the court. Including stars such as Kobe Bryant.
I think a lot of the hatred comes from the fact that he's so good it's ridiculous. He can only play for one team so 29 fanbases are going to hate him. Hating LeBron and the Heat is just 'in' right now, and has been for a while. People who refer to The Decision as a reason to hate LeBron need to get their priorities straight.
The hate didn't exist before his decision to turn his back on Cleveland and shame them in the process, pissing vitamin water all over their slack faces. Before that, he was a very good player.
A lot of the hate for Lebron comes from the fact that in this country, men don't just like a team because of players. We're more apt to cheer for our home team, and home players. Like Kevin Durant grew up where I live, and Roy Hibbert went to my high school. No one would look weird at me for cheering them on, but I am not a fan of the Thunder or the Pacers. For the most part, Americans have a free pass to hate on every team and its players that aren't local. But the people who root for teams outside the area are mostly wagon riders, unless they can show consistency in support after that great player leaves.
No one liked the Heat during the '90s unless you were from South Florida and even then, it was more likely that people there didn't like the Heat, but followed Atlanta games, since that was the most local team that showed on tv for a long time. They only became big within the past 10 years. Of course, the Thunder even less. But they're a dark horse team, and people can appreciate that more than a stacked team of mercenaries.