As I understand it, being Bretonian is about language, ethnicity, culture, way of life, and generally being more similar to Bretonians than to the other houses of Freelancer.
Seems gaians are from cambridge and generally Bretonia according to vanilla lore. Bretonian culture isnt nailed to the planet surface on Leeds. Culture is within every word someone speaks, in thoughts they have, in habbits, in what tools they use, and it goes far beyond your level of nature-loving or the current government of your nation. It doesnt change overnight. And in the Freelancer universe, it changes even slower than in our world, looking at Rheinlanders, Kusari, Bretonia, Liberty.
A brit hippie is still very much a brit, especially from the perspective of an indian souvenir shop owner.