Last night I posted an item which involved nothing in the world other than information which could be more than a little bit valuable to anybody needing to buy cars:
http://able2know.org/topic/130449-1
Sure enough, at least one of the little flock of a dozen or so idiots here have voted this item down to a zero count as usual and, in this particular case, that could have the effect of not allowing one or more A2K readers to avoid making a $5000 mistake.
In other words, the reader who missed this item because it had been voted down to a zero count would have been UNABLE TO KNOW.
I would suggest that you eliminate negative voting. That says if fifteen people find an article worth voting up, the article has a count of fifteen, and not fifteen minus X time some sort of an idiot factor.