Because losing now can cost your team everything, hence every game means everything. With a playoff system, not only might that loss not matter, but you could sneak into the playoffs with losing over 25% of your games (if a 16 team field is ued).
It greatly reduces the consequences, excitement and importance of the games with a 16 tm playoff bracket behind it.
Teams aren't magically going to start playing harder because they're in the title hunt.
Actually, I'd argue that a team like Ohio State could sleepwalk through a game like Purdue and know they are still in the title hunt afterwards.
The NFL is competitive because of the salary cap, disposable contracts and results based draft positioning.
Iowa, Boise St, Rutgers, West Virginia will still be second-class teams because of the disparity in talent. There is no draft to help them with their lesser recruiting.
That depends. An 8 team playoff would be like the current system. A 16 team playoff could do this, but would also reward a lot of mediocrity.
are you proposing an 8 team field? I've always been a fan of this (though I think 4 is a better cutoff for "elite"), and it would help protect the importance and talent of the other bowl games. If CFB stretched to 16, it would cripple the prestige and rankings of the teams invited to the non-playoff bowls.