Being able to use Bane to spread dots is an absolute huge amount of DPS increase, it's not just about Energy Drain. Depending on the mob health and the average DPS of the entire group, it's not completely uncommon to reserve 2 aetherflow stacks for bane and 1 for Excog. Energy Drain is basically just a mana recovery tool on large mob pulls so you can spam Miasma II out more if you're really struggling on mana with constant Miasma II spam.
Sure the enmity generation isn't important if they can hold aggro. But, taking less damage while the fairy heals more is a huge deal allowing you much more DPS time. Not to mention a prepull aldo will be able to absorb even more DMG before the bubble breaks, and a 20% increase on a crit-aldo pre-pull really makes me <3.
It wasn't the words "hurr durr" that I took offense to, that phrase just stood out the most. It was the unpleasant general attitude of, "I'm better then you, and you don't know what you're doing" vibe I got from it. Maybe they didn't mean it that way, but that's how it sounded.
So sure, I admit if you are top percentage rattata-tank out of all top percentage rattata-tanks. It is be possible to not drop DPS too much if the tank is savage geared and an experienced individual. Then again those tanks are as rare as unicorns. But, whether or not it'd be a net gain in DPS is highly dependent on many factors such as which dungeon it is, what's the ilvl sync, how many mobs have been aggrod, how hard those mobs hit, ETC. I could see some situations where it'd be a net gain in DPS and others as a loss.
I still stand by the statement I made, and say it's the right call for almost all situations.