> What people don’t consider is that when “we”, the people with houses, don’t spend our dollars housing homeless people, we pay sooner or later in other ways whether we want to or not when society around us partly disintegrates and additional effects start stacking up: substance abuse, violent crime, healthcare costs etc.

There's a different way to look at it as well. I don't so much pay for housing as I pay for my choice of housing. If I couldn't afford housing I'd just get whatever was deemed enough for me, the system would essentially make the choice. What i pay for is the privilege of choosing something that I want, instead of what's convenient for the system.