No one lives in a bottle. The Federation has to use money when dealing with other species, and so any Star Ship would have to have a vault... Although you have to wonder with replicators as they are, how they don't find themselves guilty of counterfeiting when visiting low tech worlds.
Look at Archer, he had to strip the platinum off his ships plumbing to pay for some crap at one point.
Starships might be fine, but lone humans wandering out there in space preaching about how money is made up and they should be allowed to take anything they want and that it not stealing, must be considered the trash of the Galaxy.