Maybe Cultural Marxism is just a conspiracy theory but the criminal Gang of Four was a very real conspiracy, and their "Great Proletarian Cultural Revolution" killed millions of people, led to destruction of cultural heritage on a scale unprecedented in modern times and plausibly set their country back quite significantly. The fact that these clearly problematic ideas are once again being taken seriously in the West (after a well-documented first flare-up of Western Maoism in the 1970s) should give us pause.
I'm not a communist, so I have little trouble in denouncing or disliking Stalinist Russia, Maoist China, etc.
I also, however, find these sorts of discussions completely disingenuous, however, in that it is conveniently left unmentioned how many millions might or might not be calculated to have died because of capitalism, cultures that have been destroyed, etc.
No one is actually willing to lay everything on the table for examination.
I think it's because capitalism is decentralised as much as possible, and decisions are made - and rewards given - as close to the people taking the risks/doing the work as possible, and so it's hard to make the case that "letting people get on with it" is to blame. Although there will be some emergent negative effects, there will also be vast emergent positive effects.
Whereas deaths due to Marxist ideology or socialist top-down policies are actually undeniably due to them, and they seem to happen pretty much everywhere it's tried.