I've been ruminating on this.
Assume encounter design stays the same. If healing is stressful as is, making healing harder in content is counterproductive to that goal, at least.
First, let's rebrand "DPS" as "actions taken to end the fight faster". I've seen mention of buffs and debuffs, but we really don't need more buttons that stop us from dying, so that leaves us with it's inverse. If SCH had a complicated rotation to debuffs the enemies' defenses, this is equivalent to a SGE blasting an enemy with lasers for the healer deeps, so let's not let mechanical flavor get in the way here.
As such, the argument in favor of the stressed healers becomes to make the healers straightforward to the point that there is no nuance and nothing interesting inherently in the role; if something is interesting, that's a new variable that can cause further stress.
But the veteran's complaint is that there is not enough complexity in the role. And because encounter design isn't changing, we would need complexity for the "end encounter faster" buttons. So healers would be discount DPS on top of keeping people alive.
So, that means we are stuck. If downtime becomes interesting and fun, then engaging with it becomes a qualifier for player skill, and the stressed will have to come to terms with that and not let this weigh upon them. I personally think the community as a whole can probably handle it; we deal with freestyle DPS and no cool down tanks well enough in the easy content.
If SE changes their minds and increase the difficulty of healing across the board so not dying is engaging in of itself, well, as said before, that's just bonus stress for the stressed out.
As such, I currently am of the mind that the bored veteran and the stressed healer cannot come to terms; their desire for the game pull in opposite directions. Not to say that this is perfect, but this is where I stand as of now...