I feel like downvoting as an concept (at least in the context of Hive type platforms) is really a failed experiment. Especially since there is money involved. People will always feel like once they see an upvote on their content, that money belongs to them even though technically it doesn't. It's just human nature.
Downvotes can be intellectually interpreted in a perfectly logical way, but emotionally it's really straightforward: "Someone gave me money, and another person went out of their way to take it away from me."
It doesn't matter how the down-voter reasons it out or even if the vote was completely justified, because the receiver of that vote only feels spite. So it becomes sort of a 'rock and a hard place' situation.
This is why I don't get involved with down-voting content except on really rare occasions. I becomes more treacherous territory as your account size grows, I'd say.