The state of the prime healing class is incredibly relevant to how a PLD or any tank should manage his gear sets. WHM is horribly overpowered. A major reason damage mitigation is not really a huge deal on PLD is because a single WHM carries so much healing efficiency and burst healing capability. Because a single WHM can max you out constantly with minimal effort (when played at a reasonable, standard level of skill), it isn't a huge deal if you're taking 800 vs. 1000 damage shots (just need to avoid to getting 1-2 shot). For this reason, you're better off focusing on damage / enmity at this stage of the game given the current endgame content.