And surely the admin has to see that the Big12 has no reason to add them.

The PAC included them for being the not-BYU (BYU "didn't fit (their) values"). But the Big12 has already included BYU, so the anti-BYU card can't be played. And since BYU now has first mover advantage, surely even yewts or yewt admin sees they don't add new markets for recruits or viewers or time zone slots.

Perhaps there is some delusion in the fan base that is fun to mock but in reality I think the majority of fans that are saying this are doing so as a desperate attempt to keep bigtiming BYU - "Your conference is our backup plan"