The majority of players that are really impatient like that probably wont even make it to level 50. VERY occasionally I get someone like that and they immediately go on my ignore list so im never grouped with them again.
That's not really that true. Many, many players are like this. Not necessarily in just this game, but many MMOs.
OT : I got grouped up today in Battle of Ilum HM on my Op healer. As I've never run that FP before, when we got to the first boss, I asked, "What does this guy do?" I got no response and just a boss pull. At the end of the run, after all bosses die, only 3 overall deaths until the last boss (2 because the dps pulled mobs instead of the tank), with no wipes, one of the dps proceeded to tell me that I was one of the worst healers he's ever seen. The last boss enraged so I said, "Good job at letting the boss enrage". He told me to not be mad that I can't do my job and I responded, "Oh, I wasn't aware that the DPS' job was to let the boss enrage." He had no response for me. So, yes, jerks exist in this game. You just have to get over it and add them to your ignore list.