There is a general tendency on the internet that any forum that promotes free speech and only moderates spam and illegal posts, but does not remove posts based on their content, becomes majority right wing after some time. There are left-wing forums with censorship, and there are right-wing forums with censorship, of course. But if you let people discuss their ideas freely without interference, the mostly tend to become right-wing. It seems that without censorship and content-based moderation artificially steering discussion left-wing ideas cannot exist.
Ignoring the vagueness of the non-terms “left wing” and “right wing”, and the baseless assertions, the bottom line is that liberalism is mainstream, and large parts of the further “left” and “right” (like socialism, anarchism, nationalism, US-libertarianism) retreat to their own communities.
Who has a need for ‘free speech and no censorship’ places?
I think it’s safe to assert that right-wing ideologies (extreme personal freedoms, or freedoms to kill unwanted peoples) tend to fit this description more. Unless someone has very unusual left-wing views, they will probably be able to find a popular place that allows them to express all the view they want to, and few will see a reason to hang around a place that is dominated by not just right-wing refugees, but the ones two noxious to be permitted in other designated right-wing forums. Why would they stick around? Hence, they are dominated by right-wing views: the further left or moderates will find constant rants about excluding races or sexuality just annoying and go back to their more pleasant forums.
What is the logical conclusion of your post? Are you implying that if the admin and mods here are extremely permissive, that socialist ideas just can’t exist? Or maybe are you implying that places like KiwiFarms are dominated by the right-wing because of reasoned ideological debate and not just edginess attracting like-minded people and revolting left-wing people more likely to be disgusted by the site topic and owner?