Weirdly they do seem to allow right wing users, or at least used to at one point (there’s a lot of users here on lw with incredibly alt-right post/modlog histories but they are still here and active) because of neutrality, although I think that is weird because I feel like maintaining neutrality is a pretty good reason to exclude them, as they skew neutrality heavily towards their audience while forcing all the normal non-extremist people out.