I feel like western leftists NEED Stalin to be a monster and NEED China to be committing genocide because otherwise they'd have to reconsider their ideological commitments against socialism.
Somehow it's not enough to ask whether there are inherent concerns in a fully centralized economy or whether China's acceptance of outside capital and extending a heavily monitored capitalist means of production is ultimately justified.
It's also somehow not enough to discuss whether China's handling of sectarian conflict along its borders or aggressive posture in Hong Kong creates more problems than it solves in the long run - because these don't invalidate the entire state or an entire socialist project.
All arguments move to invalidate the socialist project. A famine isn't enough - it must be intentional, no matter how spurious the accusation. Questionable domestic policies re: religion aren't enough - it must be concentration camps, no matter how lacking in evidence.
These arguments are taken up by Western leftists because, one, we're genuinely concerned by human suffering but we don't know how to critically parse the information we receive. We're trained since birth to accept propaganda and do not know how to navigate information.
And two, because it is easier to invalidate a successful project than it is to build a successful project. If China's largely happy and that's not the result of genocide, then it's harder to refute their socialist method, even if it's not the one you'd personally adopt.
I think that's why leftcoms and anarchists in the US whole sale swallow State Dept. mistruths so readily. Building an insurrection or revolution is very, very difficult so at least we're not as bad as them, eh? It excuses our failures at home.