(Denny Crane: "Sometimes you can only look for answers from God and failing that... and Fox News".)
Methinks the mayor is being given too much credit here. He has to decry private sector charities (organized or otherwise), because allowing them to flourish would decrease dependence on government.
There always have been, and always will be homeless...some people insist on the mendicant lifestyle (to include the likes of St. Francis of Assissi, so I do not mean this in a strictly negative connotation). Sometimes (i.e., Great Depression, Tsunami) circumstances leave relatively large segments of a population in need. When this happens, government abhors the efforts of the private sector to bring remedy and relief, and if it can not eliminate charity it will try its damndest to assume and assert control over it. I get the sense this is where the mayor is coming from....