What makes WHM special? Nothing anymore.

[EinherjarLucian]

And another thing. I think the thing about "do I have a unique ability?" should be completely subordinate to "are we contributing to the party win?". Our job, as Healers, is to go into a dungeon, raid, guildhest, FATE, or even PvP and keep the blue bars full. If we can do it better/more efficiently, or do a little more DPS ourselves, or buff our fellow party members, that's icing on the cake.

What matters, at the end of the day, is "did the tanks stay alive for the whole fight? Did the DPSers stay alive the whole fight?" If we're answering "no" to either of those questions, then we're not doing our jobs and we have a serious problem. And AST was in a position where it was answering "no" to those questions, so they got a buff.

WHM are the best/most-efficient healers, hands down.
SCH brings shields, a semi-autonomous healing pet, and damage/debuff utility.

AST brings their cards (which someone mentioned earlier, are a huge distraction if incoming damage is so high that you're focused on your job which is keeping the blue bars full...), but they bring something else: the chance to make sure that the regen/shield balance in a party is still present. An AST in the same party as the WHM should never compete with the WHM in the same way because that AST better damn well be in Nocturnal stance providing shields. An AST in the same party as a SCH should never compete with the SCH because that AST better damn well be in Diurnal providing regen.

Just keep the damn blue bars full! The ones on the left. The ones on the right we'll let our NIN/BRD/MCH pals take care of.