You just watched that game . You think Zappe would of played better? Lets remember Zappe has not gone against a real good defense. BIlls have that, and to add, a bills d-lineman almost always in the backfield as you either try to wait for a receiver to get open or you're just trying to throw the ball away.
look at the play where Mac was called for intentionally grounding. The lineman dives and misses the d-lineman completely. Mac has no time to do anything as the rush was coming straight for him. What was Zappe gonna in that situation. Move a little quicker and still get tripped up. So instead of being at the 2 yard line, you are at the 5??? With a coordinator that wont be able to call any play to help you get out of your own end zone?
Mac does deserve some blame..but he is not the biggest problem. And he doesn't need to have a great line but at least have one to keep him upright enough to make a throw here and there. Would help especially if you have no offense player makers beside the RB.