Ok, here is my point condensed.
We can't *really* explain warp drive, transporters, replicators, or their effect on economy and use/non-use of money. All of this stuff is bullshit.
But if we take something now impossible, and pretend it is true in fiction, we create a kind of equation which is played out in the show itself. Remove the lofty aim, and you lose the spirit of things. Star Trek is supposed to be inspiring, and a future of abundance is part of that.