I have no issues with the way he's been used even though I think he's capable of more. We're winning, and that trumps everything else.
Joseph is versatile enough that I don't think there's any harm being done with limiting his minutes. He'll be an important factor in the coming years though as the cap forces us to shed some salary. Joseph is one of the reasons we, as a fanbase, aren't overly worried. He looks to me like a guy who could replace a 20-25 goal-scorer pretty easily. And his playmaking is arguably better than his goal-scoring, but he hasn't really had a chance to show it off yet.