why does everyone hate rematches?
Depends on the circumstances.
For example, the BCS was by nature VERY exclusionary. 2 teams get a shot. Which likely means that a worthy team is being excluded.
Think of 2011.
LSU was 13-0. Of course they get into the BCSCG.
Behind LSU, you had three teams knotted at 11-1. Alabama (who had already lost to LSU on the field, in Tuscaloosa), Oklahoma State, and Stanford.
Now, you can make the argument that Alabama had the strongest loss of the 11-1 teams. But you can also make the argument that having lost to LSU
on their home field in Tuscaloosa, we already "knew" that LSU was better. So why not give one of the other 11-1 teams a shot? We *don't* know if either of those teams is better than LSU.
In that case I didn't like a rematch.
In a 12-team playoff? Rematches will be inevitable. But that's okay, because you can make the argument that all worthy teams (and a few unworthy teams) are in the field, so regardless of who plays who, and when, the cream should rise to the top.