I wouldn't use the term passive agressive myself--I think of that as protesting againt authority without being willing to show how you're feeling.

Whatever term you use, though, he does get his own way a lot of the time. I doubt many people could put up with it in real life. But I also think that nearly everyone who cares about him has enabled him in being this way, to the point where he's quite capable of becoming deeply unhappy if his inclinations are not consulted. And I don't mean petulantly whining--I mean unhappy enough to give up on life. While he isn't blameless, I think that those closest to him must take some of the blame. No one except John Knightley ever treats him any other way, and JK goes to the opposite extreme--becoming petulant when he doesn't get his own way.