He was taking too long to look for the passing options, and often times, didn't see many an open receiver, and by that time, the run option was not viable.
If he were in a triple option offense, he would be basically looking at only two dimensions instead of three (lack of downfield passing), and I'm sure he'd flourish. Even a run-first spread option offense that Rich Rodriguez used in West Virginia could be a nice fit for him.
Bottom line is this: He's simply not a good fit for Brian Kelly's hybrid pro-style / spread offense. He doesn't have the accuracy, and can't see the open receivers. I really, really wish that he could have fixed his accuracy issues in the spring, as that would have opened up every last page of the playbook with his amazing athleticism, but it's time to move on.