I did not assume that at all. It's just that the communists denied that greed (or, framed more nicely: self-interest) is a common human trait, so they set out t

I did not assume that at all. It's just that the communists denied that greed (or, framed more nicely: self-interest) is a common human trait, so they set out to prove that it's much better without it. And the rest is, as they say, history. My opinion is that we don't need to try that again. You appear to believe that profit-seeking cannot result in progress, and I disagree. Is that an extreme viewpoint? If you, too, consider self-interest "of the devil", capable only to destroy but not to create ("profit-seeking can [not] be a force that results in progress"), then I suppose it is an extreme viewpoint, much like the idea that the devil could be a force for good. I just don't believe in the devil, or god, but I believe that you wanting to optimize the outcome for you in a game constrained by rules that require you to create value for others in order to receive value, will end up being much better at creating value than if there was no external motivation for you.