The only other state with a comparable number of P5 programs to TX and CA is NC, and they are all basketball schools, so it's understandable that they haven't made it. Clemson is the FB school for the Carolinas, and it's in the other Carolina. So when NC State is your FB powerhouse, you aren't going to be in the playoff discussion anytime soon.
Plus TX and CA are both recruiting hotbeds, while NC is merely a sliver of the "Mid-Atlantic" region, which is more of a recruiting Luke-warm bed.