Voat was subject to a campaign planned by multiple neo-nazi communities, particularly 8chan's /pol/, to make the site unusable for non-nazis. It involved mass claiming any boards that could possibly be popular and giving them an explicitly white nationalist spin.
I can't really blame them for not stepping up to the plate and saying 'fuck off', since the genesis of the site had to do with Reddit overmoderation, and even appearing to step into the same shoes could have had killed the site.