If you think about it, the only people that deserve to be buried are true trolls posting viagra ads and those terrible scat porn stories on slashdot... and those people don't care about their karma anyway, so you might as well just delete their accounts.
Why don't we just have some kind of floor on comments. Really -1 is enough to say "this comment is crap" without resulting in a situation where someone is dogpiled.
I wouldn't vote me up that much either, but there is a difference between voting up and voting someone way down.