Every yewt fan is still excited about the Pac-12 schedule. After being beat down and just a middle-of-the-pack team later on, they'll need to pump up atendance again and ask BYU to play them again.
For USC, there isn't another USC to come to town to pump up the excitement. True Stanford and Oregon are doing pretty well right now, but it's not the same as the impact that almost all of the Pac-12 teams do for home attendance numbers at Utah.
Notre Dame helps get people excited for season tickets when they come to town and helps with nationwide ratings.