While as a healer main I hate seeing a PLD that start healing themselves when they aren't even below 50%, Clemency needs to stay. Some healers are just bad and self-healing is a way of saving yourself when you drop too low. As a very anxious tank I can completely understand how scary it can be to drop to 10-20% HP.

Other than that - PLD is literally the only tank with no self healing in the main rotation. Even on just level 50 WAR has Storm's Path and Thrill of Battle, GNB has Brutal Shell (which also gives a shield) and DRK has Soul Eater. And Clemency isn't even available at lvl 50.