Payoffs will keep our students active in sport and will eventually keep them strong and healthy which will help improve their academic results as students as well, these days sports play a great part of students that play for their college teams. In a way this can give them an incentive to do team work for any other academic tasks at hand
The reason the BCS is adopting a playoff system is because the BCS is a joke and no rational person takes a champion seriously that is voted into the game. The reason lesser college divisions already have playoffs is because they can't profit off of a bunch of meaningless bowl game sponsorships, so they use a playoff system because it's the only legitimate way to determine a champion in the first place.
A playoff system has no impact on health or academics.