You are 100% right.
My theory on Cam is that he is such a freak of nature physically that at every level he played at, he was the best athlete on the field, hands down. Even at Auburn, his size, speed and agility were hard for D1 players to deal with. Once he got to the NFL, he was still one of the best athletes but of course at that level, you are playing the best of the best. His whole playing career, his running and strong arm were always able to mask his deficiencies in reading defenses, rout tree progression, etc. Now, more than ever at the NFL level, you MUST be able to read a defense, understand tendencies and go through a 5 man progression. (Rodgers and Brees are probably the best at this). For the reasons mentioned above I believe Cam has never had to buckle down and learn these things. Another thing Cam has really not developed is his touch on the ball. Too many short passes are missed by guys because they are just rockets or don't have enough loft. Again, the guy is a future HOFer no question but his homework side is where he falls short. After so many years in the league, one has to wonder if the coaches are working toward this end or they just say "he is what he is, lets get what we can out of him."
I for one hope that Norv is meeting with this guy morning, noon and night teaching him defensive theories and what individual players tend to do in certain looks. Knowing how a pass funnel defense works and using that to your advantage versus a 4-3/tampa 2 and where to attack. Carolina's defense is not good enough to win a title this year with an above average QB but if Cam can become elite, they can make a run at the playoffs.