Eeeh, I'm never really into stories like this. "Person with lots of money, in lots of movies, actual human being!"
I'm thinking the celebs who are not so nice are actually the exception, not the rule. I mean, if we're looking at the ratio of unpleasant/rude people in the world vs pleasant/polite, the polite people are winning (or else we wouldn't have sites like etiquette hell to point out those weirdo rude people filled with commenters). I assume celebs have a similar ratio.