"A miserable place to be unless you're a billionaire." This is such a vast exaggeration, it's difficult to take your comment seriously. Is New York expensive? Yes. Is it impossible to live here, and have an enjoyable experience on $60,000/yr (even less with some sacrifices)? Not in the slightest.
"not impossible" isn't nearly the same thing as "desirable" or "worthwhile". If the strongest endorsement you can make is that it's possible to live there, that really isn't much of a recommendation.
I'm not trying to make a pro/con debate; I'm only pointing out that there are 8 million people living here, the vast majority of which are assuredly not billionaires. The original comment really provides no value by stating "I know some people in New York and they want to leave because they can't enjoy it without being billionaires."
I'd much rather live here in NYC on $60,000 than $60,000 in Oklahoma or elsewhere in middle America, unless I was raising a family. There's plenty of free or cheap stuff to do here that's very enjoyable if you enjoy a simple life.