The biggest question for the use of Esuna for me is simply "Am I needed to be doing something else more important"? Clearing ailments is important but if the party's almost dead or the tank's taking a lot of damage you can bet they're going to be my first priority. This is especially true with Warrior's Pacification from Berserk - sorry, but the penalty of me not cleansing is you not being able to attack for 2-3 more seconds (reaction/cast/application times in combo mean we're not close to preventing the whole 5 seconds in ideal situations) and unless there are literally adds spawning right now you should have established enough aggro with Berserk running that you'll be fine. If I can, you'll get it, but that's an if.
(I say this as someone who both heals and plays Warrior. I don't expect others to take care of my Pacification. It's a bonus if they can, not an obligation they are under - and it's better I know the fights well enough to not be pacified while adds are appearing to begin with)
Tangential, I think a lot don't know this, but in Thousand Maws fighting the first and second boss, cleanseing the Poison on the tank is actually worthless. The boss' AI checks if poison is on its current target to see if it should use its poison AoE or just attack normally, so it's utterly pointless to remove it off the tank because it will immediately get reapplied. (Slows from the adds don't seem to follow the same logic but it's hard to tell and harder to have a slowed target maintain aggro anyway so uh)