I think you have to look at the winners and losers in conference expansion. You trend one way, and stay on that trend.
The WAC had 16 teams.... then 8... They lost Boise and now they have none. Losers.
The Big 10... had 10... had 11... went to 12... now 14. Bigtime cable deal. Winners.
Pac 10. Had 8, went to 10, went to 12. They arent losing anyone. They can go to 14 easily. Huge improvement in earnings. Winners.
SEC. Expanded to 12 in 1991. 14 in 2012. Winners.
ACC. You can say they started this whole expansion free for all in 2004. Had 10 teams. They wanted Miami. And got them with VT and BC. And futher took 3 more BE schools. 10 + 6 - 1 = 15.5 teams with the quasi member Notre Dame. Winners even though they lost one crappy charter member with horrible finances.
Big East: Had 8. Lost the crowning jewel Miami, and two others. 8 - 3, add us and the replacements, 8 - 3 + 3 = 8. An arguably lesser 8 at that. More defections... 8 - 5, eaten up by three other conferences. Minus non-football member Notre Dame. We lost 8 teams, and finally expanded, with some relatively low hanging fruit, compared to the rest. Massive demotion in revenue. Not even known as the Big East anymore. Losers. Big time Losers.
Now let's look at the Big 12. Had it's namesake, 12. Lost two. 10. Lost two more. Replaced two. At one time was considering a merger with the Big East. 12 - 2 - 2 + 2 = 10. Love/Hate relationship with the shark and crowning jewel Texas. Status: Trending down, but not out.
To quote Ricki Bobby, "If you ain't first, you're last." To paraphrase... if you ain't winning... you are losing. The Big 12 is losing. They need to expand.