I have seen people reportly say that ND didn't deserve the spot, but there isn't any team that actually deserved it more. I think most people saying this just have an inherent bias against ND. They were 10-1, and their only loss was to Clemson, ranked #3 at the time. A&M struggled with UNC until the last few minutes of the Orange bowl, and lost in a blowout to Alabama in the regular season. Arguably speaking they may have been equally deserving, but it is understandable the committee would avoid a rematch of a blow-out loss.
OU had two losses, but there has never been a team in the CFP with more than 1 loss. And while they looked good against a FL team, I didn't see anything in the Cotton bowl that would indicate they would have done any better against AL than ND. The game, at best, would have been the same. Clearly FL had no business being in the discussion-and shouldn't have been after their loss to OU. Cincinnati was undefeated, but didn't have a good enough resume to leap over 5 other teams. And they lost their bowl game.