Here's the scary part to me. If what you guys say is actually true...that Vad Lee didn't have a firm grasp over the offense...and yet Justin was unable to take even a 10th of the snaps away from him, then that says one of three things to me:
a) Justin isn't nearly ready to step in and be the QB this year that everyone is thinking he'll be
b) Our coach is a complete idiot who doesn't know how to prepare for the possibility that his backup QB may need to produce for him at some point by getting him relevant snaps
c) Both A & B
Not sure I agree with your cause and effect conclusions here.
a) I do agree that Justin not winning more of the job last year meant that he wasn't ready last year to step in and provide an immediate improvement over Vad. Now, does that mean he won't improve over the off-season and be ready to step in this year? Not sure. I hope so, but I think the question is still unanswered.
b) I think the more likely explanation is that coach concluded that, even though Vad was not getting it right, he saw the potential there and knew the only way Vad was going to develop was to give him the vast majority of the snaps. Couple that with a), and I think that was the right coaching move for last year. However, had Vad stayed, I imagine the competition for starting QB would be wide open today, with JTs improvement this off-season being the determinative factor in next year's starter.
I agree that last year JT probably was not better than last year Vad, but that doesn't mean that next year JT necessarily won't be better than last year Vad. I for one hope so. If he is not, I think we all know how things are likely to play out.