TNC posits:
I think New Yorkers only seem more smug, because there are more people in New York and thus more arrogant New Yorkers. In my time, I have watched mo-fos from everywhere from Dallas to Cleveland to Columbia, Maryland hold forth about why their neck of the woods is touched by God. This kind of person would be that way, no matter where he or she were born. Regrettably, in New York we have more of those kinds of people, because we have more of all kinds of people. It's worth remembering the sheer population size of the city--it's like ten Detroits.
Ezra agrees. He adds:
[New Yorkers] have what's considered the greatest city in the country and can't stop talking about it. It's like an A-student bragging about his grades, or a rich guy making everybody look at his car. It's unseemly.
Martin Schneider is offended:
[C]onfronted with presumably countless examples of snobbish New Yorkers disparaging Indianapolis, Tulsa, Atlanta, or Baltimore, Klein, Coates, and Sullivan couldn't be bothered to name a single instance of anybody doing this. In this discussion, that was taken as a given, just as in a book you don't have to cite anyone to establish that Amsterdam is north of Rome. It is a truth just as self-evident, apparently.
This gets all the more astonishing if you contemplate analogous scenarios. Imagine if any of these men had endeavored to make some point about, say, Mexican-Americans in the same manner. Ahh, "Mexican-Americans are fine people and work hard, but they obsess too much about soccer and they have no interest in education," let's say. Do you think any of them would venture such a statement without casting about for some empirical evidence that what they were saying is true?