Yea, but unfortunately the admins and mods of the Tankie Triad are the biggest Tankies around and enforce that through (ironic, because they always complain about censorship) mod action

So the best course of action, if you're not on an instance that defed's from them, is to not reward their comms with activity. A total boycott, no posts, no comments, no upvotes. With a little luck, all the non-tankie users will gradually shift over