Why are new yorkers so bloody miserable?

ive been there alot with my friends and had agreat time i love the city its ace but i was there on my own a few weeks back and really noticed their down right misery. I realise everything that has happened there 9/11 an all cant have done any good but even before this they were just as rude. I like most other people have things happen in my life but i dont take my personall life out on other people. ive been to lots of big cities and spoken to lots of americans who are lovely but for some reason new york people just act like their putting on some tough guy act all the time and it gets rather boring and silly to be honest.still love the city but the people really need personality.sorry if i offended anyone abuse welcome thanks.