The Big 12's problem is that it has no current members with any sustained football success on the national level. Yes, there are one-off's like TCU's NCG appearance (the B12's lone CFP win since it started) and BYU's 84 championship, but not much outside that. Say what you want about the ACC, but it has three schools (Clemson, Florida State, and Miami) that have been powerhouses over a multi-year period. If any of those three have, say, two losses in a CFP at-large discussion vs a two-loss Big 12 school, they're likely to get the edge based simply on brand. I actually like the Big 12 in that there are no clear "have-not" programs ; anyone can move up the ladder relatively quickly. But the insecurity of their YouTube community is comical - constantly trying to down the ACC and openly rooting for its demise as if somehow they can shape perception to put their conference into the #3 spot nationally behind the SEC and B1G.