To the extent that we've made any progress at all, it's only because the societies that adopted truly terrible moral principles (e.g. communism) failed.

Communism isn't a truly terrible moral principle. It's just a moral principle that is naive and impractical as a political and economic solution given humanity as it is. A couple of elements that we would disparage as communist may actually be necessary in a post-human FAI enhanced universe in order to prevent a Hansonian hell.