Many homeless are addicts, alcoholics, mentally, criminal fugitives, or illegal immigrants.
A few are actually domestic abuse victims, runaways, disabled, or people who've fallen on hard times.
Some don't want help because they have intentionally "dropped out" of society, aren't ready to give up their addictions, or refuse to take their prescribed pysch meds as directed.
Many don't have the education or the life skills necessary to live as self-sufficient adults.
One way to clear out the homeless for a couple of weeks in Summer is to be the host city for the Democratic National Convention. When the DNC was hosted in Boston during Summer 2004, all street homeless were miraculously raptured ... to where I don't know ... but after the DNC, they were back at their regular panhandling locations.