I just don't see any
evidence of the supposed human isolation on earth. In Star Trek, humans are EVERYWHERE. We've even seen instances of a single human owning an entire planet. Humans never seem to have trouble booking a voyage on a civilian transport. Humans are seen at bars and restaurants outside of the Federation all the time. I don't know what a week on Risa costs, but plenty of humans seem able to afford it.
An offhand comment by Jake that he can't buy something because he's human just doesn't hold up to all the other evidence.