Yes. Some people just want zero responsibilities and living on the street gives them that. Living in housing always has conditions.

Is it because buildings refuse to house people with addiction problems, or that the extra $1/month is better used in their mind to get the next dose of the substance?

The roof typically comes with the stipulation of no drugs (or even rehab).

That’s untenable to the addict.

The roof also comes with a loss of any sense of personal autonomy and the threat of violence from other people in the shelter.

There's a reason people treat them as a last resort, and it's not drugs. It's that being in a shelter opens you up to abuse.

Unlike the street?

Those conditions make the offering quite different from being able to rent your own room inexpensively. One of the facets of having your own place is that you can do whatever you want there, whether it be drugs or whatever. That might not be healthy, and it's quite understandable why family would put conditions on offering a free room, but people do value their autonomy.