For many years I served on the board of a privately owned food bank. We "served the working poor" - people that were unable to make ends meet for various reasons but were still working and not receiving any government assistance. Families needed to be recommended by others on the program to verify the need. We also charged $60.00 / month (I think the average family took home around $700.00 / month in food, clothes etc.). Without help, lots of these folks would have been out on the street or on government assistance.
So, it's difficult to do a budget and save enough to have six months to a year (better yet) in liquid funds. But, a lot of folks living on the streets in "progressive" west coast cities where housing is really expensive, are there because they had no backup funds and something went wrong (illness, layoff, etc.) Once on the street it's difficult to get two months rent down payment together, not to mention just day to day living conditions we take for granted like hygiene facilities, clothing and phone, to get back on their feet again.