There are a few exceptions to this, and they would include Atlanta (where it's literally flip-flopped - probably helps that the pro sports scene is so ass), Ohio, (where people tend to care more about the Buckeyes than just about anything else), and Michigan - specifically Michigan football and State basketball, but generally I agree. All these years later I still laugh at people who still seriously think bringing Rutgers into the Big 10 gave them the NYC market. It didn't, no matter how much everyone wants to pretend it did.
Seriously, though - why is the SEC so freaking historically popular? Because of the lack of professional sports outside of Atlanta - it's all they ever had.
Having been to Atlanta a handful of times, I actually think Falcons football is more popular than UGa football within the city. But not in the rest of the state. Definitely the Hawks and Braves are more popular than Bulldog basketball or baseball.
There are a few places that have high passion for both the pro and college teams, like Ohio, Michigan, Wisconsin, and New Orleans (football only) and Texas (football only). Which team is more popular probably depends on the area of the state and which team is better.
But by and large, most markets mostly care only about the pro teams: New York, LA, Chicago, Boston, San Francisco, Philadelphia, Washington DC, Miami, Seattle, Denver, Phoenix, etc.
