I think this is most where I disagree with people on this subject: I don't tend to carry a grudge for people who want to leave the club. after all, if no one wanted to leave their club, we would never get to sign anyone! For some players, United isn't what it is to us: Ronaldo never made a secret of wanting to play for Real. being from Portugal, maybe they were the club he supported as a kid.
it's sad when a player I like leaves, but it is also sad when we get rid of certain players. But, as mad as it might seem to us, to many players it is just a job - albeit a very well paid one. I was never even mad at Heinze when those "stories" arose linking him to Liverpool.