That's a very interesting point. Perhaps, to ensure that a range of ethical frameworks have been taken into consideration (each with their varying ideas of what benevolence really means) a more equitable situation would be a plurality of utopias each with its own ruling AI? And free movement of individual humans to whichever aligns best to their own personal code of ethics.

It's most certainly in dispute. I'm disputing it right now.

You seem to think that communism is the same thing as "communism under Stalin", and that's incorrect.