well, i wasen't around, but this was doable from what i understand when the karma system was first implemented, and led to some posters being vindictive and giving negitive feedback based on the poster, not the post.
I'm sure this happens now, subconsiously or not, and certain people dont give certain other posters TP's, but i'd rather have it that way then watch people get voted out in a popularity contest. goes back tot he old "if you can't say anythign nice, don't say anythign at all" rule.