We can but praise his well intentioned desire to see homelessness ended, but none of us are holding our breath. The reasons why people end up on the street are many and varied.
However one huge driver is addiction. Accommodation can easily be provided given enough investment. However, unless one can stem the tide of drugs on our streets there will always be those struggling to stay housed, to pay rent and utilities bills.
This is a good piece from the BBC giving a rounded view of the whole picture.