The only context in which this conversation ever happens is a liberal doing nazi apologia and showing that they are more opposed to communists than they are to nazis.

We can and should (and communists, including Stalin himself when Yezhov was prosecuted, have) also be having this conversation amongst ourselves. Many were prosecuted and killed who were, according to the party itself, not guilty. This means that mistakes were made which can be learned from.

I refuse to entertain that they’re speaking in good faith.

You’re right, they’re not.