This was not only driven by vicious men, this was there from the very start, this was inherent in the revolution and its ideology, and mainly caused by real shortages stemming from economic issues
You can see it with Lenin, Stalin, Mao and Pol Pot and i'm probably only missing more examples due to ignorance. You have an economic system which is "scientific", but is actually just a mass experiment resulting in deaths of millions. And an ideology that is so sure of itself as it is "proven" it never stops or self-questions