http://www.squidoo.com/why_homeless_people_avoid_shelters#module103020341

This link above is American and doesn't quite answer the familiar grating whine that I hear every day and especially from narrow old church people 'oh can't you just go into a shelter?', but t does help towards answering it.
You have to keep scrolling down even when it looks like you have got to the end of the page.