Cunningham certainly declined, but most pocket passers also decline. He also had his best year by in year 13.
As I also displayed, many, many more injuries occur in the pocket. Many more 'big hits' occur in the pocket against a stationary QB.
I'm not arguing that they shouldn't look to have Josh run less. The concern about it vastly overblown though.
Then your argument is a fallacy. All points of data refute your assertion so then saying "Well, maybe there's something we don't know!" is not rational. On top of that, we have even more data showing that QBs take more big hits in the pocket. Why would the hits pocket passers take (which again, are more frequent) not add up on their injuries?