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.
Kiwifarms is a very biased case. It’s based, at the start, about harassing ‘lolcows’ for kicks (usually people with learning disabilities like Chris-Chan). Furthermore, it is often seen as a haven for people who get banned from other more moderate sites.
Would you agree that this inherently attracts a more edgy and “right-wing” audience?