44,000 and Moles

I recently found out that there are 44,000 homeless people in New York's five boroughs. Of those 44,000, over 6,000 spend their nights on the street. How is this possible?

Isn't there a housing crisis that has lowered the price of home and apartment ownership drastically? Aren't there government sanctions, such as Section VIII, that have allowed for reduced cost rent? Aren't there homeless shelters and all sorts of accommodations for underprivileged citizens to make use of? How is it possible for a city to be so desperate? A large portion of New York lives life above and beyond the limits of luxury while a vast population exists far below the poverty line.
How can I come to understand what it means to be homeless and live on the streets? I even hear that there are a kind of mole people - New York citizens that live in the abandoned subway stops and rail lines. I couldn't imagine living that kind of life, but for some reason the destitute nature of their existence makes me want to experience it all the more. At what other point in my life will I have the opportunity to see what it's like to live like a homeless person?

For all the atrocities that homeless living brings to the city, in all honesty the entire built environment of New York caters perfectly to the lifestyle of a homeless person. There are always people out on the streets, making it easy for homeless people to blend it. There is SO much trash and garbage overflowing from most of the garbage bins here that any homeless person would certainly never go hungry. Moreover, the maze of streets in most of the boroughs and the dark corners and parks cater perfectly to the late-night denizens not wishing to be caught or noticed, and in a city with so many flashy lights I couldn't imagine a better place for a homeless person to slip out of view than a side street or subway stop in New York city.

These are definitely questions worth pondering. Above ground, for now.