Totally agreed (and I think most people will) that even without hindsight, we knew FSU was not one of the four best. The problem is, they couldn't be left out. They did everything they needed (not drop a game, despite their best efforts) and earned a playoff spot. The best part is, they set precedent where an undefeated, underwhelming team may not get in moving forward, depending on the competition from around the nation. The way this played out was perfect.
I think moving to an 8 team playoff would truly take something away from the season. Although, every proposed change has people that say that, this one would diminish it a bit. I think the most you could go is 6 with a bye. You would pretty much guarantee every conference champ, and an open spot for an undefeated G5 or runner-up to a conference when there happen to be two absolutely dominating teams from one. This would also continue to promote great OOC games, because teams could schedule in anticipation that if they happen to lose their conference championship, but dominate their conference to that point and a powerful OOC schedule, they could still secure a spot. 8 lets teams in that might be getting hot at the right time, and at that point, why not 16?
I say let there be tension. Let there be slight controversy. If you're not clearly one of the top three and there's a bit of a logjam around #4, then accept that you might be left out. TCU may have had the same run tOSU had, or they may have flopped, but they should accept (just as tOSU would have had to accept if left out) that their body of work left questions. The great thing is that this tension is bringing change -- the Big 12 appears to either be on the path to mandate strong OOC schedules.
But, any way you look at it, we're in a great position compared to the BCS, and light years ahead of champions simply being named.