Based on the (admittedly not extensive) work I've done trying to help homeless folks get back on their feet, a lot of people do just need some money to get their life back in order. For instance, it's hard to apply for jobs when you don't have an address or a phone number for people to call you back at. Giving someone the ability to not have to worry about making their rent payment for a couple months can be huge.
But a significant portion of the cases I've seen can't be solved this simply. Despite what this article says substance abuse issues /are/ a big factor for a lot of the homeless people I've worked with. Providing cash money can alleviate some of their problems in the short term, but there are generally more fundamental obstacles that are holding people back. If you don't address these issues people can very easily fall back into the trap.
The best intervention I've ever seen for a homeless person is an employer who is willing to give them a steady job and be understanding about the difficulty of the situation they're going through. Anything that can get a homeless person to this point should be encouraged. Sometimes that can mean covering their expenses for a while to get back on their feet. But often it means providing substance abuse support; often it means teaching job skills; often it means connecting them with the right social service or civil society groups.