Well, Augusta is the capital of Maine, but if the story is about the Masters’, it means Georgia. If a Columbus story is about the military, then it is generally Columbus, GA.
If I lived in Columbus, Ga., I might see your point. But numbers tend to sort these things out. And a city with an MSA of nearly 2 million (and growing) doesn’t need a state name attached for the geographic presumption to be correct.
One other distinction Columbus, Ga., doesn’t share with Columbus (and for this you can be happy) is that Columbus (after Minneapolis) has the largest concentration of Somali immigrants in America. Frankly, I’m surprised more of these attacks haven’t taken place.