Is there a reason you just refuse to play with random people?
Honestly it's very rarely I get -such- a bad party that a dungeon takes forever or leaves a bad taste in my mouth (that's usually High roulette and hey wait a minute... that's not new players...) Most of the time the worst I see in leveling roulette is...a new person. Oh no.

Though. I think they could allow like.. double queue. Maybe not a full party.