system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it that, to the average American, Adolf Hitler is considered much more villainous than Joseph Stalin when Stalin killed millions more innocent citizens (than Hitler did) in concentration camps similar to the Holocaust?
gpt
1. Stalin did not have mass extermination camps like Hitler. He killed millions, no doubt, through ineptitude, purges of political enemies, and policies that both ignored and exacerbated famine. Stalin is probably responsible for the intentional murders of about 750,000 people. The rest of the people he killed were imprisoned (where millions died not necessarily intentionally, but through unacceptably poor conditions), or died due to famine that he did nothing to prevent or mitigate. Hitler actually devoted extensive resources to deporting literally millions of innocent civilians, based solely on their race, to camps where they were immediately executed on a massive scale. 

2. Communism isn't an evil ideology like Nazism. Communism is actually something a lot of people support, and even many who don't support say that it's a good idea in theory, but wouldn't work in the real world. Nazism on the other hand is monstrous, both in theory and practice. It was racist, totalitarian, anti-democratic, murderous. No one can claim Hitler had good ideas that were implemented improperly the way some say for Stalin.