It's not just about having a belief that their economic system is better, these people feel like they're possessed by cult like quasi-religious force, as were past ones like in the cultural revolution. It's the only way the current environment in the US makes sense because it's not logical whatsoever for this many people who grew up in Western countries to think having a revolution and replacing it with an ideology that's clearly failed is a good idea.
Why does this keep happening to human race? What is actually motivating them? Noting that these commies are insanely manipulative and dishonest therefore what they really claim to care about can all just be a front, like arguably the entire usage of race.
You have the wrong perspective. Think instead of a fisherman using a phosphorous lure ... the orchestrators of communism simply want to use other people to accomplish their own ends, unrelated to the interests of their victims. You will only understand them if you discard the illusion that they believe what they are doing is good: they know exactly what they are doing, and they are happy to kill you and anyone else to do it. They use communism because it is still easier than whips and chains.
Why do people fall for it? That's another question...
Its intoxicating to think of yourself as the victim. Its a kind of crown of pain, the whole legal system supposedly exists to protect the victim, you win the argument without reason if youre the victim.
This whole cult of communism is about victim worship.