So what? so what if he/she is a noob, a fresh level 50 or anything. We have all been there once before. The least we can do is help each other out.
If the dungeon requirement is ilvl 47 and they make it, it's not impossible to accomplish the mission. If you are the best in the group then you can carry the weaker one instead of rage quit.
The more one plays the game the better they get and if we don't have time to play it that much and are considered noob, that does not mean we should be exempt from using DF or play the game.
Stop crying and form your own group. DF is for everyone.