I have to agree that modifying encounter design risks alienating a portion of healers, even for casual content. While it's rare, roulettes show some players can barely handle normal difficulty. Then again how much of that is them focused on dps vs their job hmm? It's hard to pin down. Then the question becomes maybe that % of less skilled healers shouldn't play the role at all if dps is their priority..
But anyways imo the answer is still clear which is that for classes that the issue is more about how it feels to play ie the rotation itself is the problem. Healers just need some more creativity in the job identity department.