Earlier quoted context omitted.
Isn't it also the fact the almost no one wants to live like that? The expectations has changed and there's probably little demand for such type of housing.
People rent bedrooms in single-family homes all the time. The only difference between that and dorm-style housing is the size of the building.
The pent up demand for this is obvious to anyone who's tried to secure a room only to have a gazillion people competing with them to pay $1000+ to rent an oversized closet to sleep in.