The problem is that we want Marcus to be able to hit the 3. In these years that we aren't going to win the championship, it is probably best to get the young guys ready to play championship ball in the future. Thus, we should encourage Marcus to shoot AND hit. We invested a high pick in him, and want to see the returns.
That, or we could trade him. Not sure how much return we get on a guard who can't shoot, yet.