As the blogpost notes: "There are already lots of hidden homeless passing for normal, couch surfing, etc. People tend to not realize it."
Fortunately right now, I'm at very low risk of homelessness, but I can imagine scenarios where it could happen. Some people don't have family to fall back on. Some people's family are terrible people and it's questionable whether they are better off with them or living rough.
A lot of people live in their cars or vans for a while.
Here in Austin, urban camping was decriminalized (I am not an expert, this may not be entirely correct) and now there are quite a lot of tents popping up all over the place.
As a civilian, it's impossible for me to tell what situation a person is in; are they potentially violent, do they live in the same world as me, are they mentally and physically capable but undergoing hard times? They are all people, and they should all be helped, but help for one person isn't like help for another; and just lumping people together and parking them doesn't help anyone.