I can't speak from a healing perspective, but from a Tanking perspective you are not alone, especially in the environment that this game has created. Most people are completely indifferent exceptional ability or performance, and are harsh and damning regarding sub-par or poor performance. "Perfect" is the absolute minimum that most DPS classes expect from tanks and healers. If something goes moderately wrong, the response usually goes something like this:

You take a CRAPLOAD of damage from a BUNCH of enemies because of a TINY mistake someone made!
Lolz Bard > ...
DoodSummoner 420xx69 > wtf?
Tank/Healer > Sorry guys, I tried my best but things just didn't go right/we had bad luck
Lolz Bard > u suk, noob - l2p
Lolz Bard has left the party!
DoodSummoner 420xx69 has left the party!
Tank/Healer > Sigh....have a good one.
Healer/Tank > See ya later : /