I think we're talking about two different things. The parent comment was referring to micro apartments, which are generally rented to tenants.

Considering that many college students have two to four dormatory roommates, I don't see what's wrong with renting a small living as a young adult - provided that the living space itself is up to code.

Ah ok, I thought it was the shared mortgage idea. I see no issue with shared housing, not exactly a radical idea.

Shared housing is one thing. Shared housing with which you share major financial responsibility with someone else is another matter. Houses also require maintenance, are often upgraded over time, etc. and reasonable people can disagree about what needs to be done when and how—especially if people have significantly different financial situations.

I feel like we're going in circles. I said the same thing and was corrected (these are rentals.) I then agree, and you come in saying they're not rentals. Which is it?

Here's my stance:

Getting into a mortgage with roommates = bad.

Getting into a lease with roommates = no problem.

I was agreeing that shared rentals are fine. Well, they can have problems too but people mostly manage. As you say shared mortgages seem very risky in general.

Yeah, I think the issues that arise with roommates are well understood and generally acceptable given the benefits. Shared mortgages are insane.