The point of the upvoat/downvoat is to increase good contents visibility and shut spam away in it's trashbin.
It's become apparent since Reddit, that this comes at a cost... Content that doesn't fit a person's personal interest may become a target for that individual(or even group) to reduce its viewing potential.
That's completely against what Voat is about.. Censorship takes many forms, and that includes downvoating content that goes against your own beliefs/views to protect your own beliefs/views.
Seeing who is downvoating what content let's us know if someone is purposely brigading a subverse or a single user, in which mods/admins can then take action against the individual.
This also means that seeing who is downvoating spam can be properly thanked by the community for taking action against spammers and assisting voat's means of keeping the best content in view.
And obviously this would NOT be implemented in subs that are anonymous and I wouldn't be against a Subs choice to disable the feature entirely, but that may be cause for alarm that hiding those voats may be allowing for an agenda to be upheld -- potentially.