Why do so many healers not use specific abilities?

[tdb]

How would you save Asylum for an emergency though? It's a heal over time bubble without an instant heal. Or are people saving it for when they need slow AoE healing but are out of MP?
It's true that in dungeons it can have less uses when you have to move a lot. But for example in big pulls you can use it on the tank as another regen. Unfortunately, if you use it during dungeon bosses instead of Medica, ranged DPS often don't get inside. So I have to single-target heal them anyway.

I did say "most". Asylum is not very useful in emergencies because of the reasons you mentioned, and as such it went mostly unused for me until I learned to use it in Lv70 content. Note that I started playing around the time SB came out so I've never done Lv60 content when it was the current endgame.

I get that some WHMs like to save Benediction because it's a full heal. But I've actually seen more uses of Benediction than of Asylum.

Benediction is pretty much my last resort save button when someone takes a big hit, possibly there's another mechanic coming and all of my other instant heals are on cooldown.

The best advice I can offer us just to try to use things more. Using MP tools when youre low on MP is like putting a bandaid on a cut you made yourself - cut out the middle man, just use them whenever they're up and make sense.

That's more or less what I try to do with Lucid Dreaming and Assize. Sometimes I forget to watch my MP or CDs though. Having a BRD or MCH who uses refresh also makes me save my own restoration tools for later.

My brain handles Thin Air a bit differently because its benefit depends on what you do while the buff is active. In an attempt to optimize it I often end up not using it at all, which is certainly not optimal. Unlearning bad habits takes a lot of effort.

Cure III in casual content is often drastic overkill and I wouldn't worry about not using it much in dungeons specifically. I'd avoid Medica though - my rule of thumb is that it's a real last resort. If it isn't enough damage to justify a Medica II it can probably just wait for Assize to come off CD or get ticked up naturally. Or, again, there's always asylum.

I get skittish if the entire party has taken a significant amount of damage. If Medica II is about to end or already ended I use that; if not then Assize if it's available or will be in a couple of seconds; otherwise Medica. In many cases such damage occurs in situation where the party will be grouped up so Cure III would be a better choice, but I haven't quite finished wiring my brain to properly recognize those situations yet.