Why? The user might want to just browse the map without displaying his location on it. The user might want to just provide an address instead of his own location (assuming that function exists in the app). Why not just let the user run it, and let whatever actually needs the permission fail gracefully? Whether or not the app functionality lost is worth providing access to data gated by a permission should be up to the user, not up to the developer.
Because giving the app fake location data when the permission is denied leads to the user complaining that the map isn't showing their correct location. Apps don't want to get a bad rating for user error.
