If what you're saying is true, the issue starts and finishes with the coach, not the player. If the player isn't good enough, they should sit. But there's a human element to the game as well. I wish Harris would do well not only for his sake, but the sake of the team. If he can't improve, then Miles absolutely has the responsibility to sit him and find someone else who can get it done.
I personally think poor coaching is the cause of the qb play, and as such, said coaching needs go. How many qbs do we have to go through to prove the point?