How about this: Dart didn't choose BYU for his reasons. It is possible that he could have really sucked as the BYU QB. He could have been locker room poison. He's got skills, but who knows if he'd buy into Kalani's mantra, or think it was cheesy. If he thought that he's too good for BYU, he may have felt entitled and not put in the time or embraced system.
If he did buy in and performed as well as he has at Ole Miss all season, it probably would have been epic and BYU might still be playing.