Your friend is being really annoying, rude, and snobbish.
I grew up in the country, and I would not live in a city for anything. If I was forced to move to a city, I would not be living, I would just be staying until I could escape. I hate cities. And that's fine - it takes all kinds of people to make a world. When people ask where I'm from, I tell them I come from the country outside Washington, D.C., on the Virginia side. It's true, and I get to claim my beloved country, rather than having to claim a despised city.
But when I was in, for example, Ireland, it was a lot easier to say I grew up near D.C. They knew roughly where that was, and at least it was someplace they had heard of. People asking where you're from don't want a geography lesson 9 times out of 10. If they want more info, they'll ask. Saying the nearest major metropolitan area is very common shorthand, and when someone tells me they're from X city, I usually assume they mean they're from around there.
Also, ask your friend where she thinks she'd get all the exciting things she gets to do in the city if it weren't for us country folk? There would be no food.