Yeah, I've always maintained that there are too many people with unbounded greed for a "complete" post-scarcity to be achievable. There's a "greed is good" crowd, and then beyond that, there are those who aren't even concerned with whether it's good to be greedy, they just want to win at others' expense, spitefully. A world where they can't take from other people is not desirable. The first time I got to know someone with this attitude, I started out thinking it was a front, or a joke, but it wasn't.

The idea of post-scarcity brushes over that dark part of human nature, and assumes we can figure out how to cooperate, even absent antisocial misanthropes. In Star Trek, they have "figured it out", but the transition to post-scarcity is understandably only vaguely described.