I think they were specifically referring to Marxism-Leninism. It is “human nature” to act in your own self interest, so any system with hierarchies of decision-making power will eventually become corrupt. We just have to take a non-hierarchical path towards communism.

Do you say that you’re “boring as a person” because you don’t have any interests or hobbies, or because your interests and hobbies are so niche that you doubt anyone else would find them interesting, so you never end up talking about them?