It think it's fair to say it's combination of both of them. They're all inept.
I will admit that Cam has been very disappointing this season. I am a little worried about him, because while the playcalling and coaches on the team have been horrible, I've seen some awful things from Cam this year that's all on him. However, with saying all of that... I will not give up on Cam. I still believe in his ability, heart, and desire to be a great NFL QB.