The reality of etymology is that you don’t know what things would be called in the distant future because they would likely grow out of some common usage along the way. The Tzars of Russia drew that name from Caesars of Rome, who took their name from a bloke who also lent it to salads and a particular form of birth. Maybe in the universal dialect all species are humans in how they refer to themselves, rather than being humans from earth. Or that’s just the shorthand for a particular type of rights, because they were best codified and exported from earth; the way we today might refer to our legal systems being Greco-Roman in origin in much of the west or the way we refer to Republics today, which is much removed from the original and has more to do with the French Revolution.
So maybe it’s cool that “human rights” became the accepted term. Star Trek is pretty human centric after all, because those writing it are humans, but for an in universe explanation people also tend to contextualise stories to their own national understanding. Chinese people and American people learn about history and various concepts through very different lenses. Heck, people from Cornwall and people from Glasgow....
