> The utopian bits were never really explained, either.

What would the effects of growing up in a post-scarcity utopian society be on a human? To never fear poverty or hunger? To be sure that no matter what they do (or don’t) they will be housed and cared for as long as they live?

I assume the people in Starfleet would be the ones who are most inclined to work for their betterment, with no fear of competition, with the drive to do The Right Thing. Outside the organisation there would be people who would be totally happy in doing nothing.