One third were drug and alcohol abusers.
One third were mentally ill. Often they had been treated, but once released they don’t take the medicine prescribed for them.
One third were criminals.
There was overlap among the groups, especially substance abusers and the mentally ill.
Your survey is similar to my own experience after 25 years responding to calls with the homeless people who live in camps or along trails, etc. I would point out however that there is another group of people who actually have jobs and live in cars, vans and even motorhomes who either cannot afford normal housing or are trying to pay off debt, etc... Some of them are very frugal and principled and refuse to take handouts. I would not be at all surprised if some people posting here have been in this situation. You do not find them at shelters. These people will often hide their living arrangements from others. They keep their belongings in storage units and do not plan on staying homeless forever.
bBoy you hit a nerve with that one. I was never technically homeless, I had a home I couldn’t afford but I did have a home. I had a job, a good job that paid quite well. What I also had was a former wife who decided that she could do better alone and the courts decided that since that’s what she wanted, I needed to pay for it.
She had a boyfriend, bought him a sailboat. In the meantime I collected cans to return for nickles so I could put gas in the car so I could get to work.
But really , I’m not bitter! And I’m not homeless.