But isn't it just giving an overview, the map is showing countries as a whole. So whilst it might vary from state to state in the US, as a whole the US has no law in place to say ban smoking in certain places.
But let's say all 50 states have a law that being naked in public is illegal. But there's no federal law that states that. Based on the way these maps are compiled, if we had a map here for nakedness, even though the entire US operates under this law, the map would show the exact opposite. An "overview" for countries with distinct provinces or states just isn't possible, in my opinion.