BOTH sides need to change. Which one comes first I don't care. They can increase the healing parts of the game; its not going to stop me complaining that outside of group content DPS on healers is abysmal, uninspired and still needs to change. Especially because you and I both know they aren't going to increase the requirements enough so that we don't have any down time. Its LITERALLY not possible. Even with a smaller healing kit.
Misery is a semi-Aoe likely so that it can be used for both single target AND AOE target use. Which I don't really care for either (along with other semi-aoes because if you're going to make it do 50% less damage to everyone other than the primary target wtf is the point of it?) but until they make an AOE version (which why not SE?) I'm not going to die on that hill. I equate it more to a single target ability more than anything.
I did give it consideration. I don't agree with your reasonings and told you why. Historically WHM used more holy or Light themes in previous games. That's fine. In this game however they used Aero and Stone. Stoneskin. More elemental themed abilities. While going into Shb changed WHM to be more in line with previous iterations of itself it destroyed what it was in this game. This is what I have issue with. But I'll stick with just Holy being apart of the rotation and not get back into that debate.
Holy does not need to be more prevalent in WHM's kit. It can stay as it is as a reference to its previous incarnations. We now have Glare and Dia to support it and I'd argue the lily system as well. Giving back Stone/Aero and/or a new water damaging or support ability back to WHM both fixes the problem that mains had with the switch to Dia and Glare as well as gives WHM more to maintain. And I would prefer it over putting Holy into the rotation.
Because Holy does not equal Misery or even RDM's post melee spells. Holy being introduce into the rotation would be the same as doing Malefic into Gravity. Or using Jolt and then instead of Veraero III you use Veraero II, on a single target. The damage would be fixed (because it wouldn't be the same as if you just randomly hit it), but its just as tone deaf. I'd rather not have it.