Karma on HN is essentially ornamental but useless: it signals you've said a lot of stuff people agree with, which isn't a bad thing, but it's almost useless helping you obtain any kind of karmic balance by saying things people don't like.

What I mean is, if you've got 10k karma, there is no practical way to use it to say 10k downvotes worth of disagreeable stuff without getting rate limited or banned. It's (almost) one-way only, not so much a way of balancing good and bad.