lemmy.world got most of its users from the summer Reddit exodus. They are mostly people who care more about whether they can use their favorite Reddit app than other humans. And their admins/mods just want to be another Reddit, which is to say they socially and administratively enforce a political boundary that includes polite or socially acceptable fascism (e.g. Azov Batallion) but discludes sassy (or not) socialists. Being cringe edgelord atheists is perfectly on brand.