Good points and I agree that it is a simplistic view. On the surface though it is a concerning statistic regardless of the finer details you mentioned and its worth investigating more into as the above info represents Cams averages.
Truth be told. I believe it is a matter of Cam and Chud trying to do too much. Chud calls so many plays that fail. That when he dials up a pass, Cam is trying too hard to complete that pass. Cam is out of rhythm, and out of sorts. Call more plays he is comfortable with and his play could improve.
We aren't a WCO. But that doesn't mean you have to throw every pass down the field. We have 3 backs that can do something with the ball. Yet they get very few chances. Those type passes raise Cam's %, and give the O a shot in the arm.