I said "in many ways" not in all ways.
In many ways, perhaps most ways, Stalin and Hitler were worse than the confederacy. The confederacy didn't round up and exterminate millions of people, for example, or wage wars of conquest. It didn't engage in purges. It wasn't obsessed with world domination. It just wanted to preserve its evil ways.
But neither Stalin nor the Nazis participated in a systemic enslavement of almost half their population for the benefit of the aristocracy. (To be fair, you could argue that under Stalin, Soviet citizens were slaves to the state, and in some sense they were, but to a much more limited extent than American slaves.) They didn't make Germans or Russians have sex with each other to increase their own wealth. They didn't trade members of German or Russian families among each other. The SS and the NKVD didn't engage in systemic rape of German and Soviet women. etc.
Obviously, I'm not trying to lessen the evils of Nazism or Stalinism here. Only to suggest that the confederacy was approaching that level of evil, and ought to be treated as such, particularly among those who claim to support liberty.