Is that because they were the first to be kicked off reddit/twitter? So, reddit/twitter used to be "filled with" them?
Just think of it as part of a lifecycle then. If normal people start moving to voat, the bad people will make up a smaller and smaller percentage. Then they move to the next site, and voat becomes taken over by political forces, repeat.
Also, I'm thinking if you don't like one of the alternatives for whatever reason, is it really that hard to create one of those sites? I heard somewhere Voat was created by one guy as a hobby. A good search engine seems like it would be the most difficult one.