The reason TCU didn't get picked is b/c of three factors. Seating capicity at the stadiums (Stadiums, not just football), Total revenue produced by sports, and the number of students. Sure they have a great football program, but that isn't what counts when trying to get into a division. They look at the sports program as a whole, and what they offer for revenue.

Why would it matter that they are in Dallas, the majority of people that live in dallas can't afford to go to TCU so they go to all the other state schools in Texas. Not all of Dallas can pay 20 grand a semester to go to school. Plus it's in Fort Worth, not Dallas.