The only time players annoy me is when they clearly don't try to live up to their potential, with someone like Antonio Cassano as a classic example.
Having said all that, it is a dog eat dog world and I don't really blame him if he feels he can't be bothered to show loyalty and effort for a club that barely cares about him. He wasn't half bad trying, in his own words, at 30-40%, although he did try about 65% at Real Madrid because they deserve some effort...