Sometimes it can be a matter of players simply not being bright enough to play college-level football. They may be exceptionally physically gifted enough in high school to get them D1 schollies, but there are far more complex layers of information at this level for some kids to be able to process quickly enough, under pressure, to be effective.
I don’t know if this is the issue or not, but it does sometimes seem like some of our players are just a tad slower than opponents in making crucial decisions, throwing the timing of plays off.