I disagree. If a college/university want to join the “national league,” they should be able to do that. College sports are entertainment, nothing more. So there is no harm in having many teams/divisions in the league. That said, there should be D1, D2, D3, ... levels so that there would be realistic competition. For example, Eastern Washington University could be a D2 while the University of Washington and Washington State University could be a D1. Similar to what is FBS and FCS right now.
The whole idea of getting rid of the current conference debacle and reestablishing geographical rivalries is the right direction.
People do not want to spend their fall Saturday afternoons watching Eastern Washington University play Montana State followed by Louisiana Tech playing S.E. Vermont School for the Gender Neutral.
They want to turn on the TV and watch Ohio State v. USC and Texas v. Michigan.