Tbh, I'm not sure why they take regions such as America or France, or even Japan to base the games off of. It's Pokemon, they have the liberty to make the towns and cities as creative as they want. I mean sure taking something like the skyscrapers and incorporating that into the city is fine, but making the entire region look like a country or using the Eiffel Tower as a gym? It baffles me.
I get your complaint, but honestly, since when is anything completely original. Even the Pokémon are based, however loosely, on real-world animals, mythical beasts, and objects. Look no further than Magnemite, Trubbish, and the like to support that theory. And designing an entire region is more complex than designing a new batch of Pokémon. Therefore, its kind of understandable that they look to real-life places for inspiration to design these regions. Plus, it does give each region and each generation a level of symbolic importance, knowing that it has a real-world counterpart.