The idea that people are not friendly in New York is lunacy. I understand that people are often in a rush or preoccupied in whatever they are doing, but when it comes down to it: people are kind to each other. There are constantly women and men helping people with strollers up/down the stairs. Camille's UPS guy was the friendliest ever. People treat each other to coffee and offer suggestions. I rarely hear of anyone's need for directions going unanswered.
While we all have room for growth and a denser population allows for an increase of opportunity to run into one of the "crazies" I think most people who speak of unfriendly New Yorkers could not have spent more than a week here (in the wrong area).