China and the USSR were authoritarian state capitalist - this isn't compatible with leftist values of worker enfranchisement and equity.

I don't care that they call themselves communist any more than the DPRK calls itself democratic - they're lying, and you'd have to be a fool to trust either.

Self-reflection is necessary to have good political prescriptions, but calling Nazis scumbags or centrists weak doesn't stop that Self-reflection in any meaningful way - you'd be a fool to seriously reflect on a statement from any idiot with a bad ideology and bad take.