The truth is that it's all about eyes on TV's and the Big12 has the smallest per school population of any of the P5 conferences:

Iowa - 3.1 million
Kansas - 2.9 million (slightly smaller than Utah)
Oklahoma - 3.9 million
West Virginia - 1.9 million (smaller than Utah)
Texas - 27.0 million
Total - 38.8 million
Average per School - 3.9 million

Let's compare that to the conference 90%+ of CB wants to join, the PAC 10+2:

Arizona - 6.7 million
California - 38.8 million
Colorado - 5.4 million
Oregon - 4.0 million
Utah - 2.9 million
Washington - 7.1 million
Total - 64.9 million
Average per School - 5.4 million

That extra 1.5 million eyeballs per school makes a huge difference in the value of a conference.

Getting UT/TT/OU/OSU would have been HUGE for the PAC. Truth be told, UT was absolutely STUPID to pass up the chance to join the PAC10. The fact is, if UT was willing to give up the idiotic LHN, Larry Scott would take those four schools in a heart beat. All it would take would be for the ACC to take WVU and the B1G to take Kansas and the Big12 GOR falls apart, and there would only be 4 major conferences.