It's a nonsense statement that is yet another excuse to ignore what happened in the ring.

If the challenger has to do significantly better than you your championship is fraudulent and thus meaningless.

The sport needs to drop all these cliches that are nothing but excuses to deny the truth. Fans seem to act as though they hate when fighters make excuses but fans make excuses incessantly. Describe the fight as it happened and decide the winner as it happened.