Because the only problem here is the one in your head.
You do bring up a good point about knowing DoTs, however, the only time prior to SB that I actually saw other healer DoTs was in 8 and 24 man content, as my PLD alt was something that was getting leveled on the side (like maybe an instance or two every week) for most of HW, and actually something getting played since SB because of the cracked clusters.
Thin Air only buys me 12 seconds of no mana costs, which is about 5 or so Holy (or Aero 3) casts with Presence of Mind before Holy starts eating my mana pool. A lot of what I'm balancing is whether or not I can do enough DPS to the mobs combined with the other party DPS so that we're down to something I can reasonably manage with Cure 2 by the time both Thin Air and PoM fall off or not.
The other thing to keep in mind is that Thin Air + Lucid Dreaming are pretty awesome for mana regeneration, so there's consideration on where we are in the instance prior to the next boss, as having both Thin Air and Lucid Dreaming. Most of the time this isn't an issue with Thin Air, but the cooldown on Presence of Mind needs to be planned around a little bit so that I have it and can chaingun off Stone 4's on the boss at 1.8s cast with PoM up.
There's a lot more that I'm taking into consideration in instance than just "large group of mobs therefore go AoE mode", and that's probably true of almost any good healer.
Eh no, I don't want to have to deal with the drama created when some idiot DPSer starts harassing someone else in the party because they aren't up to their "standards" - more out of concern for my fellow player than myself, really.
The number of DPS that this has been an issue with (from my experience), shows that expecting the DPS to do that is only going to lead to increased healing load on the healer.
Then why are you, and several others, calling me a "bad healer" and attempting to tell me stuff I already know about WHM?
Again, if all of the WHM quests were healing centric... wouldn't that get kinda boring?
I think that's a bigger issue with SE, as they really don't take a strong stance one way or the other.... thus these threads.
You know, if you had said something more clever, like:
Follow the ABCs of WHM: Always Be Casting
That remark might have been a bit more to the point....