He's not hurt, he's just not that good [in your traditional sense] as a QB.
In the right offense with enough talent with enough creative play-calling he's a world-beater, but with the receivers he has now he's not going to be able to succeed on a regular basis.
That being said, he still doesn't really turn the ball over [often], he's still a threat with his legs and when in a rhythm he can start piling up passing yards.
This team lived off the PA-pass-keep-option last year and dominated. This time opposing D's have done an excellent job of [mostly] taking away his roll-out by keeping a spy always ready on the weak side. This should mean that you have man-coverage down-field, which is a good thing for our receivers, but unfortunately they can't shake their coverage.
I blame most of RWs struggles on the talent on the outside. But he hasn't helped himself. He doesn't seem confident in the pocket.