All of Undeadfire's demands are based around unilaterally buffing PLD's dps and nerfing every other tank's utility. Someone who was interested purely in min/max gameplay wouldn't waste their time arguing about self-sustain gameplay. What, are we all trying to maximize our healing per second now?
Having DRK absorb HP with Carve and Spit would be lore breaking. Everyone knows that PLD is the master of vampiric magicks, which is why their Abyssal Spirit/Abyssal Circle spells are probably more efficient for healing than their classical Clemency spell. PLD is the new Moira now, doesn't want to throw healing orb.