The biggest issue with shelters is also that they're incredibly unsafe, much of the time. Rape, robbery, and assault are commonplace.
Y: "There are too many homeless here, it feels unsafe."
A: "How dare you! Those are human beings!"
Y: "Why can't they stay in shelters?"
A: "They feel unsafe, there are too many homeless there."
It would be funny if it weren't tragic.Besides, it's almost like different homeless people are... different... people.
It's not a rational choice but sexual assault does not often result in (or come from) rational decisions.