A 12 team playoff is a huge improvement. Everyone will have at least some sort of path to the national championship (although some won't be entirely played out on the field). Perhaps someday every team will be able to play their way into a national championship on the field but we aren't there yet. However, the top 6 conference champs will get an automatic berth (almost always including the winner of the Big 12). Even the winners of the PAC and ACC and sometimes even the MWC might be included. And a 12 team playoff provides a lot more access then a 2 team playoff or a four team playoff.
And as a college football fan, we get two more rounds (4 games each round) of incredible, meaningful college football. I can understand that it sucks that 7-5 N Texas can't win CUSA and get destroyed by Georgia but there is still going to be a lot of fun games coming to a TV near you soon.
And did I mention that BYU is part of the club now with a path to make the playoff available to them every year?