It's funny you say that because that is the concept down here. I always thought that too until I moved there. I really grew to really like the people up there. I was still in High School and remember the kids in NY were more real. Not as many cliques, popularity contests, and other issues that were common in schools I attended in Texas. Texans are known for being friendly but I remember when kids from the northeast would move down here, the Texas kids would give them a hard time calling them "yankee", etc. When I moved to New York I was expecting the same or worse treatment. I was shocked that the kids were real cool to me and were fascinated that I was from Texas. I immediately became popular in school and all the kids called me "Tex".
New Yorkers for the most part are cool and easy to get along with once you learn their sense of humor and ways. The difference between a New Yorker and a Texan is a New Yorker will tell you to your face what he thinks of you. A Texan will smile at you, be polite then curse you behind your back if he doesn't care for you. I like the fact that you always know where you stand with people up there.
When you say loudmouth jerks I think of Philly and Eagle fan. I lived there too. Philly fans are just aholes. That's why I hate the Eagles and Flyers.
New Englanders on the other hand ....