Downvoting and upvoting are really both about disagreement with rewards. If you believe a post is worth more, you upvote it. If you think it is worth less you downvote it. Ideally, in such a system the best posts would tend to get the most rewards. Large stakeholders should act in this manner because in theory that is what is in the best interest of hive and what is in the best interest of hive is also in the best interest of stakeholders. Of course, all this depends on people acting rationally...
RE: You cannot take away from the author that which does not belong to the author.