This "law of karma" is the westernized thought of what karma is. In the original culture and context it isn't positive, negative, or neutral for that matter. It's actually more about someones reputation within a community. So the idea of positive atraction and doing things for others does apply but it was never meant to be a mystical force around to punnish and reward people. It is, like life, simply what you make of it. This more closely relates to your reputation score rather than curating some missed content that deserved reconition (hidden gem post) then receiving a massive upvote reward for your positive actions.