"New markets" was never the Big 12's expansion mantra. "Names" and "availability" were. We were desperate when we added TCU, and we were FAR more interested in interesting matchups (and if you question this, check the ratings on the Texas/WVU game) than new markets, given our league's financial model.
Look back on the chatter while it was all going down. Almost no one viewed Louisville as a miss at the time. Hindsight has changed that view (perhaps rightfully so), but I think it pointless to judge decisions on the basis of information that came to light well after said decision was made. Louisville has a great athletic department, but its pretty clear that the networks do not believe they add financial value to the Big 12, and conference strength is pretty much equivalent with finances.