I'm not sure I understand this comparison. What conference are you comparing the Big 12s foot print too? As best as I can tell those cities are in 3 different conferences.Big 12 was never going to be the preeminent conference because it lacked population for TV markets, its football teams could never over come this.
Dallas
Houston
Kansas City
St Louis
Denver
These were just not going to over whelm the people trying to sell ad revenue when you compare it to:
New York
Baltimore
Atlanta
Miami
Chicago
New Orleans