It's really just a matter of numbers. There are 8 million people living in New York City, so even if only 1% of them are honest you're still going to have 80,000 honest people there. That's bigger than many rural counties in the U.S.
You don't have to live in NYC very long to figure out that the place is filled with reprehensible degenerates.
True, statistically humans are a sinful lot. But clearly, they are not all bad apples.