In that neither coaches or probably management want to deal with the other issues each player brings. Now those issues aren't the same but I think the principle is. With Jimmer no coach wants to deal with a bunch of fans chanting for jimmer to get into the game all game ala the New York situation. I don't think Jimmer warrants that type of passion, jimmer probably doesn't even think so. It's easier to get some other guy probably as good that doesn't come with the crazy fanbase to sit on the end of your bench.
Jimmer is no doubt good enough to be on an NBA team. Saying "5 teams didn't think so" is not very well thought out. There are other issues at play I believe.