The offensive package he runs has no identity. He will run the option, keep it and slide. WTF is that all about? If you're going to be an option running QB you doing freaking slide. I assume someone taught him that. It's like they don't know how to use him.
I haven't ever thought as JJ being anything but an average college QB. Last year, he occasionally threw groups of accurate passes but was never what I would call a consistently accurate QB. Based on one game, I say the kid from McNeese is a more accurate than JJ but that leads into the whole QB recruiting mess. Your question is why is he worse this year. I believe it is a combination of lack of confidence, teams knowing how to defend against him, Crowton's playcalling and losing the confidence of his teamates. So a little bit of everything have combined to make him a below average college QB. I wish I saw something that might reverse his descent.
In response to the OP I think the pressure and competition Lee has brought to the table, all the way from the Spring Game, has mentally taken JJ off his game. Last season, his role was to limit turnovers and do exactly what the coaches asked. This season he is under more pressure to make plays himself and lead this team. He has also been under pressure to prove himself worthy of being named the starting QB for LSU since he was picked this fall and I think mentally that has affected him. Just my $0.02
I have said it before and I will say it again, JJ does not have the football sense to play qb amongst top notch competition. Not quick enough, mentally and as a result, the speed of the game overtakes him, and then it is all downhill. Seems like a nice kid, certainly an awesome athlete, but I don't feel he is up to the task from the mental/decision making perspective. Not saying he is unintelligent, just that he appears slow to process and then take the appropriate action.
It worked better than what he is doing right now! If he needs the coaches to make some of the reads for him to take off some of the pressure, then I say bring it back for him. The OP asked what happened between last season and this season and this is a legit difference.
REALLY? As in plural? Hard to believe someone would come across ONE person so unscrupulous much less two or more. Any coach so spineless would have to be a loser cause not being able to make the tough decisions more than likely permeates throughout his overall persona.