That hit home.
This has been a problem in WoW for a long time. I remember back in TBC a Warrior applying to my guild when I was GM.
We put him through his paces in 5 mans as a test of his tanking skills and he struggled. He was a friend of someone in the guild and new to the game, had a good attitude but just lacked the knowledge.
After the run I had a long discussion with him about class mechanics and tanking on Vent, being the main tank and class leader (yes class leaders that old dead concept from classic of people who gave advice and looked after their class in guild).
I helped him to up his game, and he became a valued member. In the end I told people to remember when they were new, their own mistakes and learning, to have patience and help him out. He became one of our most dedicated raiders.
Today that is happening less and less, everyone is just totally rude with no patience whatsoever because everyone they always group with are strangers and it has no impact on them.
Kudos to the guy who helped the outcast warrior out, it says a lot for the kind of person he is.