The first 10K or so units would be for the homeless. But, after that you can rent them out for some small amount to anyone that needs it.
Just imagine, if you're homeless and it's raining. What would you prefer? live in the streets or live in a small micro apartment? Sure, not everyone wants one, but why not give people more choices? Right now, your only choices are this: 2 million dollar condo or 20$ tent under a bridge. Let's give people more options?