For me, I tend to give him the benefit of the doubt because I thought the offense maintained better than expected production through the QB carousel, and I saw a lot of plays where there was opportunity for success and failure was due to a player or players.
That said, I don't claim he's great, but I thought, especially based on being a rookie OC, he performed as well as could be expected given the circumstances.
Moreover, I find the Hackett bashing annoying because for every knowledgeable poster who has a reasonable basis for ripping on him there are 10 morons who have no idea what they're talking about. 90% of the guys that whine about play-calling don't know what plays are being called, what blocks are being missed, and what open receivers aren't being thrown to. They just know we didn't score and that makes them sad.