LOL exactly. I was thinking this too.
I'm from Atlanta. I am more specifically from Stone Mountain(been living there since I was 5) and went to college in the city and now live in the city(also went to sunday school in the city for most of my childhood). But overall I consider myself from Atlanta. Most people don't actually live in the city and the city is not very big. I don't have a problem with people living in the surrounding burbs saying they are from atlanta. Atlanta is definitely more than just downtown and the area inside the perimeter, like it or not. For people from Atlanta, I say I'm from stone mountain since they'll know what I'm talking about and I think that's on my fb too.
Atlanta(including burbs in the meto counties) is definitely different from the rest of Georgia. Also when I was living in Stone Mountain, I just lived there, went hs there and did groceries there. All social activities were in the city. Over here everyone drives 20 mile easily one way to do anything unless you live in the city(which I do now it feels like heaven to me). And that includes visiting friends in other burbs on top of meeting up in the city.
I do find it odd that bothers you. Maybe Boston is different, idk.