After E8S, I promised myself I would play another role instead

[ForteNightshade]

I think some of what you said is subjective. Like Diadem rework. The gathering instance that is diadem now is actually pretty chill and fun. But we wen't through 2 iterations if count the original before we got what we have now. Although its very focused content which is either leveling your gathering classes or getting materials for Ishgard crafting. Drk also being terrible is hyperbole as the tanks have all been very close in performance and playstyle. Pretty sure world first for Ultimate content was with a DRK for Ultima and Bahamut. Also the way you talk about WHM as if it was never viable class is silly. All classes are and have always been viable in this game, but you are correct to say that some classes are more desirable then others.

Seriously? We're still bringing up the World First UCoB clear? One player enjoying Dark Knight doesn't negate the massive vocal criticism it received—enough the devs overhauled the job despite said clear. That overhaul led to further criticism because what they landed on is essentially Edgy Warrior. As for White Mage, no one is arguing about its viability but rather it's desirability. Ask any White Mage player just how hard it was finding a static that didn't subsequent ask if you'd switch to Astro after prog. Why? Because Astro was objectively better at nearly everything by 4.3. Not only did it have comparable (or superior) healer tools but offered buffs White Mage couldn't. There was simply no reason to play White Mage much in the same way Black Mage, Samurai and Monk all suffered. They were all inferior to their respectively counterparts.

You mention Diadem but it took three separate attempts for them to land on an decent alternative. That isn't what I call a ringing endorsement considering the lofty expectations they had for Daidem's original concept.

A part of the problem is that message boards and chatroom tend to be echo chambers for people of specific kinds of opinions so it can be hard to gauge actual reality and perception when people are being extreme and irrational with their critique of gameplay elements. However they do seem to notice when certain issues reach a fever pitch if you will. Look at monk. The stagnation of it finally made it to their ears and they've stated there will be big changes in the future. I do think you make a salient point though that they haven't even made a statement as to possible changes for healers. I'm not saying feedback is wrong, but I don't think hysteria on message boards is an efficient way of conveying the message.

Let's look at Monk. It took them four years to finally make changes the community had been asking for. In fact, they notoriously said Monk was the job they were "most proud of" during the Shadowbringers media tour. This despite taking literally none of the feedback offered. Monks complained at length over the slow down of RoH; that they had too many GL related abilities to either maintain or drop their stacks, and they had no means of attacking when forced to disengage. Monk's overhaul came due to the playerbase being so fed up with their feedback getting ignored, they stopped playing the Monk. In essence, they forced the dev team to listen. If anything, that only highlights EaMett and Liam's points. The dev team can be incredibly stubborn when it comes to feedback in spite of them constantly asking for it.