The general player base needs to improve

[ThirdChild_ZKI]

Pharos Sirius, the first new dungeon we ever got, was nerfed.
Expert roulette/Daily content is intentionally kept at a low level of difficulty, both for convenience, and because they don't want players to feel blocked
Crystal Tower was nerfed internally before we every got to play it because the devs thought it was "too hard for players". It still proved to be one of the harder Alliance Raids we've ever had after that fact.
Coil saw several nerfs each time the content became old, to the point of some turns being a shell of their former self.
Steps of Faith was nerfed into oblivion.
SE is on record saying they wouldn't make any Ex trials as difficult after Thordan
Players petitioned to make sure Weeping City was NOT nerfed.

. . .If the average level of the community were fine, none of the above would've been a concern.

And if they don't know any better, you think they'll magically learn to AOE when you tell them how to in the same dungeon you are playing with them? I'll answer for you, they won't. And then my guess is that we'll go to the "I assume they are refusing to learn/they don't care" bit and proceed to kick them thinking you are being politically correct here.

You assume too much in immediately jumping to kicking the player. And realistically, there's no way for a player to not know what AoE skills they have available. Sure, some might not read tooltips, but who doesn't try out new skills when they get them? Fact is, it would take an active effort or absolute, complete, I've-never-touched-this-job-ever levels of competence to completely ignore AoE skills legitimately. But again, the difference between someone who legit doesn't know and someone who's just not trying is often quite clear. And I would hardly expect someone who actually doesn't know something to be hostile in being offered advice in a civil manner. As for someone not trying, if they get defiant, as I said before, either one of us is free to leave.