It's cheating because the city limits are what they are. Chicago's city population doesn't include all of Cook County; Cleveland's numbers don't include all of Cuyahoga County; Detroit's doesn't include Wayne County in its entirety, Pittsburgh's city numbers don't include all of Allegheny County; Baltimore City is completely separate from Baltimore County, etc. etc.
The city's boundaries are what they are, for better or worse. St. Louis has very small city limits. It's not fair to claim it's the 12th biggest city unless the above-mentioned cities (and many others) are allowed to include their principle surrounding counties as well.
That's just ridiculous. When people talk about how big a city is, common usage is to refer to the metro area. When you say Dallas/Ft. Worth is the fifth largest city in the country, you aren't just referring to Dallas and Ft. Worth. You are including Arlington, Plano, Irving, etc. When you talk about how big Washington D.C. is, people don't mean just the distric of columbia, they are also including VA and MD counties.
If they had said St. Louis was the 42nd (or whatever) largest city, basing it only on the 350k in the city limits, THAT would have been misleading because the average viewer would expect them to be referring to the metro area.






