Long time reader here.
I agree that we are headed for an eight-team playoff and agree that it would be exciting. But it will not eliminate controversy and not just when the SEC will claim three spots each year. The problem will be the location for these games. Multi-week playoffs work in the NFL and in lower divisions of college football because they play games in the stadiums of higher seeds. But NFL fans accept that a 12-4 Green Bay deserves that home field over a 10-6 Dallas as we take NFL schedules as somewhat balanced (even though they are not). But home games are a tricky matter in FBS as the fight to get the home field--which would be a huge advantage--would involve a lot of politics. Sure the 8th seed is happy to be there and would not complain, this year for example, in traveling to Clemson or Alabama, but would ND be psyched about having to go to say Norman if OU earned the 4th spot and the Irish the 5th when the teams are pretty close based on resumes?
Or they may keep them in the traditional bowl locations, but that would be hugely unfair to the Big Ten and Notre Dame. Except for the very rich, fans of Northern schools are not going to travel to Dallas for week one, then Phoenix for the national semis and then say Pasadena for the title game. A fan of a Big 12 school or Pac 12 south would be more likely to do so. And, of course, the southern schools would not have to travel too much as you know they will want power teams playing close by in round one to help attendance. We have already witnessed Miami winning national titles after playing in the Orange Bowl, LSU after playing in New Orleans and USC after playing in nearby Pasadena. This would be worse. ND probably has an advantage in that the base is national but how many MSU fans are in the deep South? To win a title, Sparty would have to play three straight games in which they should expect a significant disadvantage in the size of the crowds, especially in the first two rounds.