Currently there is no method of countering a down vote. When/if an account reaches a rep of 10 then that account should not be able to down vote. This solves the issue of petty "I['m going to piss people off" down vote accounts like sunsetjesus. We all saw over on steem how ignoring one tiny account ended up leading to lot and lots and lots of tiny accounts.
Down votes are needed, however there is no method to counter a down vote un-like the ability to counter an up vote. There is no need for a down voter to worry if they can not be down voted or effected by counter down votes.
If the rewards are removed then what reason for creating content? What makes Hive different than Twitter or Facebook, or youtube?
If/when a down vote is issued, and if people disagree with the down vote, then the down vote needs to be able to be down voted. As an example your post has a large down vote, some people disagree with said down vote. It is supposedly the people that decide what a post is valued at, yet we have only a one way voting system. If the down vote was able to be down voted, then the value portion of the anti-down vote would then be added back into the value previously voted for. 10 people down vote smooth's down vote for a total value of 8 dollars/hive, that amount on day 7 is added back to the post value. The people have spoken up and down and settled the value where it the community agrees.