The Star Trek TV shows are full of contradictions themselves. In one you hear there is no more currency, that “we work to better ourselves”. In the next one, you hear about gold-pressed latinum. All the science is fake, anyway. Roddenberry had a staff of people who actually knew some real science, but rarely listened to them.
My response would have been, "Then talent, skill, and a better you is your currency."
eg. Was there one episode where Kirk didn't smash the "Prime Directive" to smithereens?
And if they were supposed to go where now one has gone before how come everywhere they go there is someone already there?
Actually, it makes sense... There's no currency within the Federation, since there's unlimited, free energy, and technology that allows anyone to have anything they want or need. So it makes sense that in order to have meaning in life, one would want to try work on oneself.
On the other hand, outside the Federation, it makes sense that currency would be required. And supposedly gold-pressed latinum can't be synthesized by replicators.
Mark
Even in the original Star Trek, in Starfleet you earned “credits” and “spent” them.