I'll stand here and advocate for the 12-game playoff.
(1) We already made the switch to a playoff format, where teams would get second chances against teams they had lost to earlier in the season. That came about with the conference championship games, and was reinforced with the four-team playoff.
(2) For all the talk about how Arizona State (B12) didn't belong, they sure look liked they belonged against the loser of the SEC championship game. That's not nothing. The bigger point is that the big conferences have always argued that their teams are far superior to everyone else--and to parrot the Big Ten and SEC, even the Pac 12, Big 12, and ACC didn't belong. (Let's try to overlook that a Pac 12 team stepped into the Big Ten and dominated it.) Clemson won several national championships recently, Tennessee, Alabama, aTm, and South Carolina haven't exactly shown just how amazing the SEC is relative to everyone else. The reality is that the margins between these teams, even across conferences, is smaller than the fans of the helmet schools want everyone to believe. The 12-team playoff gives the ASUs and BSUs a chance. As Oregon just demonstrated, the fact that they lost doesn't mean they shouldn't have had that chance. Could it have worked as 8 teams? Sure. But 12 isn't necessarily wrong just because we've had a few uncompetitive games.
(3) We all know that winning a game by a couple of points doesn't mean that team is necessarily the better team. It was better on that day, but we've had this discussion over and over again. So if we're trying to find the best teams, we shouldn't punish a team (too much) for one or two small losses.
I wish we could go back to the NCAA/bowl system, but that's probably more nostalgia than anything else. What I really wish is that Wisconsin was one of the teams that made it into the 12-team playoff. :-)