Their offense objectively sucks. They have one guy who's a 1 trick pony with running the back...once you lock that down, he's absolutely awful.
The other guy was even worse...he had negative yards.
Their O line blows, which makes that bad QB situation even worse and it kills their run game.
The piece we don't know about is if their defense is actually good or not.
And keep in mind we already watched them struggle mightily against Nevada. The game against BYU wasn't some random one-off.