nothing nonsensical about this. would just mean that most landlords would have to rent out properties they own outright. in such a market a sufficiently large entity could potentially get better loan terms that allow them to build/buy a building and still achieve positive cashflow. or it might be okay with having negative cashflow while building equity over time (to break even in the long run, rent only has to exceed the interest + maintenance). this could even be a mechanism by which rent < typical mortgage payment in the first place.