The Ncaa's playoff system might only be four teams, but those four teams will represent the best of the conferences. By opening it up wider you are neglecting the fact that some teams weren't good enough to have the best conference record, or the best record in college football. In order to be apart of the 4 team playoff, you have to be the best of the best. Like the BCS system, each win has an amount on it, and the teams with the highest totals will be chosen the by the 12 man panel.
Also, the longer you make the seasons last, the longer the players are on the field, which in turn could result in injuries thus ruining their NFL careers. The four man playoff is for the best of the best. Not the 10-2 sun belt team that had one big win and is ranked 11th based solely on their record.
the NCAA should make the playoffs bigger because it will effect the NFL to. It will effect the NFL by seeing which players are good in clutch situations or against better teams. So the more games you play against better teams the more clutch it shows you are. One team could be ranked one but isn't good against other ranked teams