As someone who used to have similar views(Ukraine, xinjiang, etc), the answer lies in Western propaganda. I think it's because of the the reporting on these issues often includes facts that are deeply woven in to the propaganda, in a way that approaching the subjects the same way you would other news can easily lead you astray. Combine this with the fact that Western audiences are not going to be familiar with the subject matter, materialist analysis becomes actively difficult using strategies that will probably serve you well on other issues.

The way I realized my error is that I pulled a Marxist Descartes, where I did not trust any Us Media sources and rebuild my opinions from scratch using international and academic sources.

I think it's important to put the context what statements like these mean for most communists (this is mostly those lurking in these discussions that are not MLs themselves). The goal is not to vindicate Stalin, I think most people you left the spaces have serious problems with some of his actions. The point is a rejection of the western narrative. The history of the Soviet Union fed to us by the West is built on lies and propaganda, designed to give us a mental model of an a state that is inherently "authoritarian" and evil. By building a new mental model of Stalin and the Soviet Union, we can understand and criticize it from a Marxist lens.

For what it's worth, most threads criticizing China on lemmygrad seldom have liberals interfering. I'm not sure why, but my guess is that threads criticizing China go against the narratives they often use to dismiss leftist ideas.

Hopefully I'm packitng to the choir here, but passing with a VPN is also a good idea.

I think what's particularly insidious about this article are the underlying assumptions. To understand why it considers the results of the study it examines striking you need to conceptualize society in a strict hierarchy. The wealthy and intellectuals at the top who are above things like racism, sexism, and the like. And the bottom, with the lowbrow and ignorant commoners who are susceptible to such things. The essential assumption is that those at the top are too good for these disgusting opinions, when most reasonable people know that's not the case.

Ultimately, this goes back to the marketing that made racism "unacceptable" in the United States. It's crime, is not being unjust, it's being common. The flaw of the poor, uneducated whites. The proper response, of course, is to dilute every culture and ethnicity, through capital, into being pseudowhite torch bearers of the cause of liberalism.