One reason is an extremely sophisticated audience.

Tanya Steel: I think New York City is probably the hardest city in the world to make it for a chef.  I think one reason is that the rents are so high that you already are boxed into creating a certain kind of restaurant.  I think another reason is that the population is so sophisticated and really knows what they’re doing; and knows that if you don’t know what you’re doing, they’ll call you on it right then and there.  I think that the level of criticism in the city professionally is the highest of any city that I can think of.  London would be a close second, but New York City by far.  The level of sophistication of the restaurant critics here is phenomenal.  So people really know that if you’re making a … they know what that …should taste like.  You can’t pull the wool over anyone’s eyes here.  So I think that’s why New York is so hard for critics.  And you know it’s the old Frank Sinatra song.  If you can make it here you can make it anywhere, and it is really true.