I like this conceptually, but pragmatically I do not see its advantage. I think one way to do something similar is to keep karma split into positive and negative karma. I am currently around 75 karma, but my hunches tell me that is probably +125 -50. Someone sitting at +125 -50 is different than +250 -175 or +80 -5.

Having bad karma get its own bucket is less demeaning than having it change your entire "score". It is still bad but you can still get a feel good from the positive scores.

(Edit) Oh, Jordan said the same thing. Please ignore this comment.