^^
This, pretty much.
I mean, if you are playing a Healer, or a Tank, then you know.... if you're not familiar with the role (let alone the class!), then common sense would tell you that you should practice that stuff in lower level dungeons before you jump into a Level 50 dungeon?
Yes, Jump Potions and PotD exist, but that doesn't mean you can't Q up for something like Tam-Tara or something just to make sure you got the basic concepts down before deciding that something like Amdapor Keep is where you ought to be trying to learn how to heal.
If a player decides not to put any kind of effort into learning how to actually play (which PotD does NOT teach you), and you jump into a dungeon, then you expect people to get irate with your lack of skill and knowledge of how to do your job. That's not Elitism on their part, it's a purposeful lack of effort on yours.