Lemmy.ml is the instance admin’d by the developers of Lemmy, who are Marxists. Lemmy.world is admin’d and moderated by liberals who generally are hostile towards Marxism, and have defederated from the 2 largest explicitly Marxist instances as a result.

Users generally prefer Lemmy.ml or Lemmy.world depending on their opinions on Marxism and Communism vs liberalism and Capitalism. We are on Lemmy.world right now, which is going to have far more people agreeing with OP than if this was posted on Lemmy.ml, where users hold the opposite opinion, that Lemmy.world is a problem (generally).