First, let me clarify: I'm not talking about now, I'm talking about when he first took the identity. Do you like the idea that he and Bruce had a fight and they split off from each other, or that Dick just felt he had outgrown the role and it was time to move on? It's been done both ways: Judas Contract made it just a personal choice, but that was changed by COIE. BTAS had the falling out, but in Young Justice, he seems to have just moved on (hasn't been shown, but there is no apparent tension between Bruce and Dick, and it wouldn't make sense to me for them to have that in the time gap but for it to ultimately never matter at all).
So which do you prefer? Personally, I like the idea that he just felt ready to move on. I never really liked that conflict, and Judas Contract made the transition beautifully. I just think it makes the identity look better. If he did it on his own, it really is him just maturing and becoming his own man. If he was fired from the role or did it out of anger at Bruce, it makes it look a lot less like maturing and more like a teenage rebellion.