Homelessness, Is Society To Blame?

We see them everyday, sleeping underbridges, with cardboard signs, a cup in hand....
do you have any spare change they ask?

What happened? where did we or they go wrong. Is it their fault? Should they
"just go get a job"? Many people have different opinions and views on this subject, but are we not our brothers keepers?

So the question is who is to blame?