I don’t like the expanded playoffs in baseball either. 162 games is the longest regular season of any professional sport, and there’s enough parity between teams at that level that the outcome of a 3, 5, or even 7 game series is pretty close to random. I think the new system this year doesn’t do enough to reward the teams who proved they were the best over the long season.
If the expanded playoff for college football “backfires” though, I think it will be for the opposite reason. There’s significantly less parity in the sport than there is in MLB, and football tends to be a less random game than baseball anyway. If people are getting tired of the playoffs always being some combination of the same 5-6 teams now when the field is 4 and they have to go undefeated or at most have 1 loss to another quality team to make it, just wait until the field expands and it’s going to take 2, maybe even 3 losses to keep teams like Georgia, Alabama, and Ohio State out.