I actually saw a post on another message board that said, definitively, "We will not repeat as champions with Cardale at quarterback".
I don't really have a horse in this battle, because I think both of these QBs are excellent and we're in fine hands with either* (provided they actually get to take all the reps, and don't have to look over their shoulder every series).
But I can say, for the people who support Cardale, there's a definite short memory being displayed by the camp that seems to be "anti"-CJ. I watched someone yesterday cherry pick turnovers/TDs from the Bama, Oregon, Hawaii, and NIU games, without giving him credit for Wisconsin (because, in this person's view, Wisconsin's defense was "terrible") or VT.
So while, yes, it doesn't add up that a B1G QB of the Year/Team Captain/Etc = backup, it can similarly be said about Big Ten Championship MVP, Sugar Bowl Champion QB, National Championship QB, Guy who was getting some pretty good draft grades = backup.