That's a good point. Downvoting can have different uses or justifications and also different effects. Given the nature of Hive, imagine if people were downvoted based on political, religious, racial, or any other agendas? How would anyone increase their rep or HP? What would be the point of a Blockchain whose crypto assets can't grow? What would be the point of promoting it as a real decentralized platform where free speech is truly respected? Rewards continue being the main motivation for people to post here instead of on Twitter, Facebook, or YouTube. Unless the downvote option is used fairly, I do not see the point.
They way they are using it now is like punishing the children for the sins of people who are not even their relatives.