Iowa State is not going back to playing teams like Grinnell or Simpson as they did in their early years. Why? There is no butthurt. Iowa State does not care about those teams. They are not suitable candidates to compete against a team like ISU for a championship. They don't bring much fan interest or revenue. They are yesterday's news to ISU. ISU has everything to lose and nothing to gain by playing them. ISU would be upset if someone dumped them in a division of 'purist' CFB with those regional and historical 'rivals.'
Everybody has his own definition of who matters enough to be in the club, and a great many people think they are one of those who matter. There are not 72 serious contenders for the CFB national crown. The last team outside the new P2 and not named Miami, FSU, ND, or Clemson (aka the candidates already named as potentially ripe for taking by P2) to win a championship was Washington, who shared the title over 30 years ago, before Leach ever coordinated an offense or most Americans had heard of the internet.
A nationwide 'purist' CFB consortium sounds great for people who don't want to watch a lot of blue blooded, red-faced, hate-inspired, championship-implications, etc type football. Great. Make the league and good luck against Grinnell. The system, for better or worse, has evolved from what some people seem to want (loose regional divisions) to what we are witnessing. Teams don't play high schools or city teams any more, and I am glad. I would rather see more games against Bama, UGA, LSU, OU, Arkansas, Florida, Auburn, and the like.
If other teams "left behind" disagree with the logic, they are welcome to structure their next conference without using the criteria Texas, USC, OU, and UCLA have employed. My suspicion, though, is that they will do the exact same thing. They will decline to fill their schedule with teams in their backyards and instead play games that, on balance, look more exciting, more challenging, more lucrative, and less strictly 'regional.' Because it makes sense.