I've seen more salty tanks than healers
I play both and healer role definitely generates more angst. As a tank i look mostly at mobs and bosses - how to position them right, how to mitigate etc. Healers look at the party list and they can't avert they eyes from those bard w/o Straight Shot and dragoon who constantly forgets to reapply their buff. At the people standing in all sorts of shit. At the tank who use all their CDs simultaneously or pulls three packs in Deliverance.
And when healer says something in line of "hey can you please use this and not stand in that" its usually a shitstorm. Last time i said to a tank that skeleton in Sirensong can be stunned to avoid his draw in - aoe attack they laughed, said that its a cross-role and they doesnt need it anyway... and then both them and their BLM friend proceed to stand in all aoes at last boss just for the lulz and i think they meant to kick me after wipe. Well, we still killed the boss despite that... but the salt was real.