Quote Originally Posted by Beytran70 View Post
It is just a coin to most, objectively, but with the blessing of the Goddess of Fate it is recognized as universally valuable.
The Eorzean goddess of fate. Why would it have any inherent meaning at all to a culture that doesn't revere the Twelve?

Personally, Gil being a not just universal, but multiversal currency is one of those things I just sort of hand wave away as a gameplay convenience thing. Lore need not apply (see also, aetherytes in Elpis, etc.)