I've never weighed-in on the issue, but it was always my opinion that McCoy would be a good quarterback if the offensive line were improved and a real offensive coordinator were put in charge of the playcalling.
I think I've changed my mind, though. He seems to make poor decisions and bad throws even when he's not under pressure.
Just as one example, he goes deep way too often when the runningback has slipped open in the middle for an easy 8 yards.
Maybe that's the coaches decision. I don't know. It all just looks so... ill-advised.