I think the tenant system needs looking at because it puts people in a position where what happens to their belongs depends entirely on the behaviour of another player. The owner goes inactive, they lose all the fixtures in their room, possibly some furniture along with access to a house.

Tenancy is a good stop-gap while houses are in such desperately short supply. I can see that allowing tenants to take over a house where the owner goes inactive or wants to relinquish could be very problematic and open to abuse, so I understand why Square don't allow it.
However, I don't see why they cannot save the entire contents of a tenant's room and store it indefinitely so they can become a tenant elsewhere or transfer all their stuff to the new apartment housing when it becomes available. Same with people who are kicked from their FC.