I believe the problem is as Sebazy said that they don't care where the tanks and healers come from as long as they exist.
To a businessman, there is no difference between having a stable, dedicated playerbase of a role and an everchanging one where people get replaced at the same speed they quit.
They stripped away as much role-specific responsibility from tanks and healers alike as possible so anyone, including people who aren't really interested in the role, can just do it.
And this approach currently works... somewhat. The numbers are still fine, healers and tanks exist, although healers had some drops on numbers (not as informed about tanks). But it's not terribly skewed towards dps so it must be fine - except that alienating veterans by telling them to fuck off so little Timmy can enjoy his fast queue times isn't a good look.
Making something accessible is good, deleting as much extra responsibility until you become borderline obsolete isn't.
And that is also why "just play dps" isn't the solution.
Neither for sending a message nor for giving the unsatisfied healer mains what they want.
It doesn't send a message because SE accounted for that by instead focussing on just always getting enough fresh meat to wear out.
It doesn't give the people who are unhappy what they want because while dps gameplay is generally more engaging instead of mashing your one button to death unless you have a clownfiesta party, it still lacks what these people really enjoy about the role: noticable and real extra responsibility, juggling different tasks, making meaninful choices, being able to show good reaction with triage healing.
I had switched from healer to BLM for the 1st EW tier.
And I love BLM. I really do and it is the one class I will miss.
It has a high skill ceiling, it's extremely rewarding to pull it off well, it requires equal amounts of planning for mobility and reaction to procs and MP ticks, it has very meaningful choices via Transpose lines/ doing short AF phases and optimizing UI phase, taught me how to keep my movement minimal but precise and even my Addle had to be planned more carefully because of the limited amount of instants to weave it properly.
It was fun, no doubt.
But it also lacked what I really want and that is the extra responsibility of keeping the party alive, of supporting the team as a whole, of juggling different tasks (as opposed all of them being focused on moar deeps), coordinating with my co heal and the party as a whole and feeling like I approach the same problem from different angles whenever I switch class.
It is why I'm so happy with playing healers in WoW again.
I've spent 40% at most dpsing in LFR which is basically normal raids and easiest difficulty but with slightly more chaos and carnage and I mean that in a good way
And I have a lot of room for improvement as if there's almost no end to what I can polish. Not just in the downtime gameplay department but also healing itself.
When I switch from Druid to Priest to Evoker to Paladin etc. I always have a completely different approach and a fresh challenge. Even the downtime gameplay is different between healers. Some go into melee combat, some stay at range and some downtime gameplay plays directly into getting resources for healing. They have different utility and ways to support their party.
That is what I'm looking for and playing a DPS in FFXIV isn't going to give it to me. Despite the frequent assumption that I "secretly just want to play DPS".
No, I don't. End of story.