Just that easy huh? Housing-first programs work well for people who are willing to be housed and treated. But if the housing comes with any rules regarding substance abuse, many of these people will refuse it. Some others will agree but then destroy whatever housing they're given, or they revert to crime. These aren't exceptional cases; like I said before, somewhere around half of homeless people are addicts, and a signifanct proportion have severe mental health issues. We can throw as many resources as we want at trying to treat people who refuse treatment, and house people who continually sabotage themselves, and still end up in a situation where the streets (or prison) remains the end game.

I've seen a lot of this first hand. I can see you have strong opinions, but I would encourage you to actually learn a bit about it, maybe volunteer at a shelter or with a treatment and placement organization.