It provides other users with an at a glance idea of your reputation, without chasing a “high score”. Could always rank users based on up/down votes, as I said, but limit the range so that as long as you’ve been active for a few months and aren’t a douchebag, your score will be maxed out.
Maybe we could still have karma, but display it as a ratio of good:bad karma or something? Active user and most of your interactions get upvoted, green dot. New user or not active for a while? Gray dot. Established user and all your content gets downvoted all the time, red dot.
Get banned from 50+ subreddits? Your color dot gets changed to a picture of u/spez.
Slashdot did so many things right. +5 Insightful.