I recall typing up this nice well-formed post for this topic, but I can't find it...so I guess that means I got distracted and closed the window!!
So time for the quick and dirty method (because I still want to comment but I'm lazy):
Although a party of nothing but the base level character in a KQ has a much higher chance of failing, it doesn't mean that a KQ of nothing but the highest levels won't fail as well.
People get excited about seeing a new KQ. I know I do. New music and requirements and people. It's information overload for people their first time in a new KQ. The earlier you learn what to do, the better you can react when you're higher level doing it.
I hate leeches as much as the next person...putting people on auto follow and just going afk without saying anything =.= rude.
Since most quests at my level are bugged, I sometimes get bored grinding and pop into a KQ. It perks me up with the change of pace, and I'm usually pretty good at explaining the objectives to new visitors of the KQ.

Quick and dirty version was still long. SORRY!