What's with the new players today?

[Issac]

But I also don't want them to play a vital role like tank, which is supposed to guide the party through the dungeon, and being completely oblivious about what awaits ahead. Really, please, play dps or healer, something that doesn't have the responsability of being the party's head, learn your dungeon, and then go tank it.

I was with you all the way until the above quoted. I don't agree.
Darkhold popped because of roulette, right? Roulette is for new players, it helps keep the older dungeons that need to be cleared in use. If the new player is a tank, just roll with it and try to be patient. And of course if the person is disrespectful and unwilling to learn, you can lose that patience, that's completely understandable.

But in my opinion, we should not expect new players to just level a class other than tank for everything when they want to play tank. That's unreasonable. Let them play as they like.