If you're right and that's the definition some people use, I'm not surprised they're confused. Considering I see most people using "midwest" referring to places like Ohio and Michigan.
I've always preferred "Great Plains" when trying to describe my general location to folks online. You say "I live in the midwest" and everyone seems to assume you're in Ohio or Indiana or thereabouts. Nope, I'm in South Dakota. America's a big place, y'all. The middle of Colorado is where I draw the line - west of there you're not Midwest or Great Plains, you're in The West.