I am going to assume that in different parts of the county the situation for the homeless or very poor is, well, different.  Where I live, there is almost no reason for a mentally stable person who is a little motivated to go hungry--we've got that covered.  In addition, there is at least temporary housing available for non-addicts/non-violent people.  This leaves 3 groups--the untreated and significantly mentally ill, the addicts, and the lazy.  Usually, there is crossover between these categories--many are all three at once (which makes sense, if you think about it).  That being said, you simply do not see people starving in the streets--and this is a very good thing! 
I suspect there are other parts of the country that don't quite work this way, I understand.
If you want to help people give them the opportunity, and the assistance, to help themselves.  It is NOT just opportunity, it is NOT just assistance--it's both.  If you were on the street, wouldn't you want someone to do that for you?