Undone
All-American
Why not throw it in every once and a while?
There are several good answers to this question. But this is the biggest one: You only have a set amount of hours you're allowed to practice, so you only have so much time to train your QB. So you wind up sacrificing time that you could be spending increasing your QB's passing ability with practicing these pretty difficult concepts that you're saying you'll ultimately wind up using pretty infrequently in games.
The risk/reward just isn't there.
It would also imply that Sims is the QB. And I think it would be unwise to not leverage as much practice time as possible trying to improve the passing performance of a QB like him.