for a handful of years prior to getting the job.
He obviously doesn't have a complex system which isn't necessarily a bad thing but people questioning his coaching acumen isn't that far fetched imo.
Personally I think he does as well as I would expect BYU to do based on their players/recruiting so I don't get to up in arms about him, though I also think he's far from a defensive genius and think its reasonable for him to be criticized by fans.
With that said, Iliasa's rise in the coaching world was pretty remarkable and I tip my hat to him.. though I think that was more a personality/friend thing than based on performance.