It's not terribly uncommon to que for low level roulettes and get something like the Stone Vigil and to be partied with people who have literally no idea how to play their class at level 41. It's frustrating when a run takes an extra 10-15 minutes because the only skill your summoner has hotkeyed is Ruin, or your tank think's Riot Blade is their bread and butter and at the same time sad to think what a piss-poor game experience they probably have since they're probably constantly votekicked and raged at. You can try to mentor them and sometimes it works, but a lot of times they flat out ignore friendly advice or say they understand then continue spamming riot blade. Since this game tries to appeal to both the console and casual markets, we get a lot of first-time MMOers who are probably doesn't even know about the trinity of party make-up. I can't help but feel that adding a small level 15 class tutorial (to be done before queing for Satasha) in which the players need to demonstrate a basic understanding of their class would make both their experience and that of everyone they play with much better.

Tutorials would explain the basics of the class, then ask them to demonstrate their new knowledge with something like:
-Summoner has to kill 3 targets within a time limit which can only be achieved through DoTing multiple targets.
-Tanks have to demonstrate they can hold aoe aggro while fighting with NPCs and that they can hold single-target aggro against a friendly NPC that deals substantial damage.
-Monk/Dragoon/Nin? must burn down a single target, but should be difficult to achieve without proper use of positional skills or combos.