As far as MCN, mixed feelings about him personally, but that's another discussion for another day.
As far as what he says in here, I generally agree with him. Most homeless are a)mentally ill b)drunk/high or c)both. A cop told me once that the best way to tell if a panhandler is actually a street person is to look at their hands. If they are really living on the streets their hands will be obviously rough looking. I personally never give money to panhandlers ever. Some years ago, there was a guy who I would see frequently around on the streets near where I lived, he never asked me for money a single time. In hindsight, I kind of wonder what his story was, but in reality I know he's almost certainly dead.