It's not the 12 best. Its currently the 6 conference champions and then the "6 next best". (perhaps they will change it to 5 given the PAC12 collapse) Given that format, its still going to be hard for a non conference champion to enter.
I find it amusing that so many want Clemson to continue to play a cupcake schedule and have an easier path the the football playoff in lieu of having them play a more difficult schedule. Any extra money they get, is not going to make them better than the traditional SEC powers.