When talking about the healer role and especially WHM, it's not about a few animations or a bit of flavour here and there.
Every class will constantly undergo change and some like it, some don't. That's normal.
If a change caused an uproar for good reason (= design failures) and clearly doesn't resonate well with a large part of its playerbase it was not treated as "Tough luck, buddy. Play something else". It got fixed. MNK underwent multiple reworks, some of them mid-expansion, NIN got fixed quite fast at the start of ShB because it was the least popular melees caused by poor design choices.
But having a clunky clip mage that was both last in dps and healing while having atrocious mobilty for an entire expansion with only one very brief moment of glory in speedruns that lasted only a few weeks was a-okay.
That's not a matter of personally not liking something.

What is an objectively poor design choice is that the vast majority of a healer's toolkit is designed around fights that don't exist.
To give a comparison: imagine being melee but the majority of the fight, you can't stand near the hitbox because there's a death zone. So while you have 15 melee skills, you end up using your 2 ranged skills the majority of the time. That is objectively bad design.

A business generally aims to please as many people at once as possible.
The FFXIV playerbase is heterogeneous and you have everything from a grandma with slowpoke reaction playing her first MMO once per months to hardcore players that raid on multiple chars for 1st week clears and that is where "easy to play, hard to master" comes into play. A job can absolutely be accessible to grandma while still being fun and interesting for experienced players.
They chose only to please the lowest end of the playerbase that doesn't even stick with the role for most part with their healer design choices while alienating many, many veteran healers that made up a signifcant and reliable part of the healer playerbase and that is bad.
That has nothing to do with feelings, not liking the new flavour or some changes to the class fantasy like WHM going from earth/ wind/ water elementals to light.
Telling someone to "just play something else lol" doesn't work here, not when the entire role suffers from the same issue in every content, at every difficulty level and not when they have bend over backwards to adjust other jobs mid-tier to please the vocal players that were unhappy with some choices because they simply weren't thought through properly and couldn't hold up in practice (looking at you, oGCD Mudras) and certainly not when we know that it's possible to find a middle ground that keeps it accessible for new players while being interesting for veteran players.

You don't like having to be near melee range on a caster? No problem, BLM got you.
You don't like being rooted to the ground for 30s every 2min? Unlock RDM, win.
Love to play piano on your keyboard? NIN is for you.
Cycle with multiple combos instead of a rigid rotation? Try SAM.
Fan of buttons lighting up from procs? DNC.
Don't like to spam 1111? Tough luck, chose another role or another game.

We have different classes for each role so they can appeal on more than just a superficial aesthetics level to players: through unique gameplay like low APM vs high APM, flexible priority lists vs rigid rotations, meaningful class gimmicks like AF/ UI etc. And they succeeded with the dps role and to an extend with tanks as well.
But there isn't even a single healer that accounts for the insane amount of downtime the entire role has by design.
We keep getting more buttons to heal scratches and the incoming damage keeps getting lowered while dps and tanks also get more skills to help with mitigation and healing - which is fine, mind you. I wholeheartedly support tanks and dps being able to play a more active role in party mitigation/ healing.
But the fact remains that they succeeded in making the role accessible but utterly failed at keeping it fun and interesting at gameplay levels above "I have no idea what I'm doing hehe".
For some unfathomable reason it's completely fine that this is true for an entire role while they bend over backwards to make dps accessible, fun, engaging and full of variety.
And healers certainly don't lack the vocal part of the community, nobody can say that the devs could possibly be unaware of this issue because nobody mentions it. Nor can they accuse the vocal part of wanting to make everything super-hardcore and roadblock newbies when most suggestions point to the contrary.

Why has the vocal part of the healer playerbase been asking for years for more downtime options? Because that's the one thing that wouldn't make the primary function (healing) unneccessarily hard for new players.