Found some new lore on this:3

It seems like the culture, by which Eorzea is defined, is not really all that different from the culture of the other continents:
"(About the Hyuran)They brought with them many skills and beliefs and formed the driving force behind the rapid cultural revolution of Eorzea."
Btw, this sentence is about a past cultural revolution, not the one today with the shift in numbers to adventurers, the new technology from Garlemald, etc.

If the cultures of the continents are similar, is the term "Eorzea" geographical, after all?