He's clearly not as driven as some of the top players, that's pretty obvious. Which is why it's important that he plays for a manager who understands him, can motivate him and get the best out of him. Good managers recognise this is as being a key skill in their job and get difficult players to perform on a weekly basis.
We've got Pardew. He doesn't have these skills, doesn't understand him, blames him, can't motivate him so he's going to sell him at a loss. Poor Alan.