I will say the o-line also sucks so he does have at least one "excuse". He also did play much better last year when he had some protection and Carter at receiver.
That being said I would think running 3 different RB's the switching back and forth with the backups, weak receiving core... weak o-line all factor in why the team sucks. I honestly think they'd be better off chucking it deep every play and hope to get a PI or reception...