The problem you run into with a playoff is that it just keeps expanding and you end up with too many teams. It's what happened with the NCAA basketball tourney, FCS football playoffs, etc.
It happens with every playoff in any sport. They'll just want to keep expanding it because you're still going to have teams complaining about being left out.
Before you know it, we'll have teams with 7-5 records that haven't beaten a single ranked opponent getting into a playoff.
A +1 playoff is the only scenario that makes sense, using BCS rankings and keeping the 4 major bowls in tact. The conferences aren't going to lose control of that money, I don't give a sh*t who complains about it. It's not going to happen.