To quote the Honorable Justice John Marshall Harlan II, speaking of the First Amendment right to freedom of speech;

To many, the immediate consequence of this freedom may often appear to be only verbal tumult, discord, and even offensive utterance. These are, however, within established limits, in truth necessary side effects of the broader enduring values which the process of open debate permits us to achieve. That the air may at times seem filled with verbal cacophony is, in this sense not a sign of weakness but of strength. [A]bsent a more particularized and compelling reason for its actions, the State may not, consistently with the First and Fourteenth Amendments, make the simple public display of this single four-letter expletive a criminal offense.

How is what this group doing consistent with the First Amendment?

Then you're entirely wrong. Banning users for exercising the spirit of free speech is what Voat is against. If you thought you could act like niggers from Somalia going into Europe, you were mistaken. They could have had heavy moderation, allowed users to make whatever dumb comments they want, and allow the users to let the downvotes do the heavy work. They chose none of that. No, they chose Reddit style censorship, which is odd since you all just escaped from that.