Sure, Utah "sells out" it's games, which is a feat, but in the actual biggest
game of the year last year, Arizona at home, a lot of the sold seats were pretty empty throughout the game.
Utah does a better job selling their seats (sellouts are the biggest scam in sports by the way) and showing up for big name opponents, but since Arizona doesn't have a name, people stay away.
Also helps Utah that most of it's fan base is within a 45 minute drive.