It's a real attitude, but it's a very rude one, and it's rather short-sighted as well.
However, there is a decided cultural divide between "Yankees" (most commonly, people from the northeastern United States) and "Southerners" (people from the southeastern United States). People from the western half of the country are usually members of neither camp.
The cultural divide shows up in language, notions of what makes good hospitality, interpersonal interactions, and a variety of other things. The mistake that the person quoted in the OP made was not in recognizing that there are differences, but in assuming that one region was better than the other. And to be completely honest, southerners are not guilty of this particular attitude any more often than northerners are. Northerners call southerners uneducated hicks and rednecks, and southerners call northerners unrefined boors who wouldn't know good manners if they smacked them in the face.