Why do people from Ohio hate LeBron James so much?

I have a few thoughts about my last week activities (see previous posts), that I'll write as soon as my brain recovers. But one thing that was noticeable was how, everytime I went to a bar and the Miami Heat were playing against Oklahoma, everybody was rooting for the Thunders. And I wasn't even in Cleveland. Yes, I know LeBron James is the Ohio young prodigy that used to play for the Cavaliers, so many feel betrayed when he moved to Miami. But wasn't he following exactly the American ideal: go where your best interest lies? I go to Southern Califonia often, and I've never heard any Lakers fanatic ranting against Shaquille O'Neal when he went to play for the Heat. Why the hatred against LeBron James? I don't know much about him beyond how he plays, but what i witnessed last week didn't make much sense to me. And I doubt there were so many people from Oklahoma in town last week, watching their team in a bar.