Absolutely pathetic attitude on here. Cesc has done two things:
1) Leave Arsenal for Barca. He spent 6 years at Barca and 7 at Arsenal, so they're both "home" just as much. And in those 7 years at Arsenal where he was one of the best in the league, he won 1 single FA Cup. An extremely talented player gave you 7 years of his career and got little in return, and so wanted to move to his home country and actually win something.
2) Leave Barca for Chelsea. He was forced out and his first choice was Arsenal, but Wenger (his "father figure") rejected him. He had very few options left, and even if he had the choice of any club in the world, he had no reason to be loyal to Arsenal any more.
What exactly has he done wrong here?