I do think that part of the issue is just cultural. Living out here, people don't care. Here in SoCal, basketball is 90% Lakers/Clippers unless you or a family member attended UCLA. College football is slightly bigger, but I expect that will trend down a lot now that we have two Los Angeles NFL teams. I suspect a lot of USC fans [non-students and non-alum] will more naturally shift to the Rams or Chargers than continue to follow USC.
California in general has an extremely robust college system, with a BUNCH of UC schools outside of the two who have real sports (UCLA / Cal), and USC and Stanford are small elite private schools. Most people who go to college end up at any number of other UC campuses, at Cal State campuses, or any number of other private schools.
I think AZ, OR, WA are better culturally for college football, as those states basically have two "big" schools vying for eyeballs instead of the multitude in CA. But I think compared to the 800-lb gorilla (CA population), it's not enough to move the needle of a PAC-12 network.
I think there's a cultural problem, and I'm not sure how to fix it.