Commendations are a joke, don't even pay attention to them.
It automatically goes to tank/healer a lot of the time
And people too lazy to commend anyone unless you done something very impressive and just exit once they get the 5 they needed for challenge log (I'm guilty of this)

PUGs/PF/DF tend to be more hostile than FC/Friends so expect it.
If your FC is really mean, find a new one.
But do understand, people do get frustrated wiping over and over again especially same mistakes, when they have the raid/primal on farm and is just there to teach new people.