Mr R.
Thank you. It is _NOT_ at all a burden when i know you and others are real people seeking understanding. (in contrast, those that have multiple aliases just to deceive and create chaos.) 
Many people, like you, the only homeless they really have exposure to are the "very visible" homeless. Those that have hit a point of being so emotionally beat up that they really just don't care any more, or they have lapsed into a mental state that this is their new "normal" of reality. And that is the really scary part, how do you turn them back from that state of mental abyss? It is a long and difficult process to undo the damage.
I have heard it said before, people will become exactly how you treat them. If you treat them respectably, they will excel. If you treat them mean, they will become mean (bullies are taught to be bullies), and if you treat them like animals, they will become like animals.
There are thousands of others that are homeless, you will never know it unless they tell you.