One thing that caught my eye in Grim's post yesterday about what Northerners secretly think was the idea that New Yorkers don't have to go anywhere, because everyone comes to them eventually. That was probably fairly true for a long time, when New York was still on the make. After a while, it becomes an attitude of decay; the rest of the world does eventually start building alternatives when you act like you can sit around waiting for them to come acknowledge your awesomeness.
Google links if that's a paywall: South Carolina boost from Panama Canal expansion; New York not ready. Too busy working on those sugary drinks and salty restaurant offerings.