Property ownership is an abstract concept enforced by law in the first place. There are theoretical economic models which do away with it to varying extents, or implement alternative ownership models. Why is it so mind-boggling to modify how it works in one specific instance?

Actually, almost everywhere, when you have a tenant, you lose some ownership rights already, by law. For example, except in an emergency, you generally can't enter the building without prior notice.

The issue is not that acquiring a tenant restricts some rights that the owner would otherwise have; this is a compromise that the landlord knowingly makes when he rents. That control is relinquished for a pre-agreed, limited period of time, after which control will be returned to the owner, is the essence of renting. The issue is that some people seem to believe that once they are on someone's property, that person loses the future ability to determine how that property is used; i.e., it's not that they have to wait until the current contract expires, but rather that you seem to be arguing that the landlord should never be able to remove a tenant from his property if the tenant does not consent, even at points when the lease on the property has lapsed. That's a permanent deprivation of the core of ownership -- the ability to determine and direct the utilization or exploitation of the property, even if you have to fill existing contractual obligations first, like an active lease.

> The issue is that some people seem to believe that once they are on someone's property, that person loses the future ability to determine how that property is used...

Here's the thing, though. It's not as if existing rent control regulation catches landlords by surprise. If a prospective landlord is so unprepared as to be unaware of the rent control status of a property that he's planning on purchasing, then he's likely to do very poorly with pretty much all of the tasks that being a landlord requires of him.

In short, the fact that landlords rent out rent-controlled units is proof positive that they understand and accept the restraints imposed on them by rent control regulations. The fact that rent controlled apartments continue to be rented in SF (rather than withdrawn from the market for five years and converted into condos, as the law allows) is proof that rent control is not draining the lifeblood out of landlords.

The insane rents in SF are not due to rent control (how could they be?), but due to the pathological lack of new residential construction.

Rent control doesn't grant tenants a permanent interest in the property, even if some rent control regulations make it annoying and/or arduous to remove tenants. The person I replied to suggested that landlords should be required to let their tenants stay in their property eternally if the tenant so chose, i.e., that tenants should have permanent control of the property.

You absolutely can alter the concept of property ownership; to think otherwise is a failure of imagination, historical perspective, or both. (For instance: who owned the land under the buildings at 8th and Market three million years ago? What would an early Christian think of our complex system of interest-bearing loans? Have you ever read any sci-fi novels depicting societies in which property rights took fundamentally different forms? Should landlords be allowed to kill or enslave tenants if that would increase their profits? What if the government knocks on your door and claims eminent domain? And so on.)

Whether you should do so is another question, one to which I don't have the answer.

I think your view of property ownership is a bit out of touch with reality. It's pretty rare that having a deed to a piece of land lets you do whatever you want with it. Or even close to whatever you want.