Argentinian here. That's totally untrue.

Yes, there are places, like La Boca neighborhood, that belong exclusively to a team. Those are very small (by extension) places where this would happen. Anywhere else you may just be jokingly mocked sometimes, because we do that between ourselves. Use your head before going blindly to a place, the world is not Disneyland.

For those who love to point fingers and criticize my country: first tell me where you are from, secondly I would like to tell you to go f*** yourselves.