Instead of trying to segregate some people, why don't you look at the problem itself?
The problem isn't people being douche to each other, the problem is Blizzard using the item level as the player "ranking" instead of creating a legitimate PVE score.
If you were matched with people of your own skill level, you would eliminate all these problems, and maybe introduce an incentive for people to get better.
Nobody, and I'm sure it's nobody, enjoy carrying people.