[observer]

To 10023's comment:

New York has more wealth than Chicago. By an incredible amount. As a result, it makes sense to build tall, thin skyscrapers because the sale price or rent price can support the tall construction premiums.

On a side note: those point towers in NY benefit a lot from their ability to still use scissors stairs (not allowed anymore in Chicago and most places for that matter). Makes a huge difference. I would have thought they would have been outlawed after 911. But they were not.