Ok, not sure if you really wanted a response here. Always feel awkward responding to a one-sentence comment with an essay, but to answer your question, this is required. Or TL:DR: companies exist for limited liability, and limited liability is grossly inappropriate for rental housing.

We've really lost the plot with what corporations and limited liability were invented for. The original idea behind incorporation was that it allowed people to invest in something with many other people, and to limit individual investor losses on risky megaprojects.

The early corporations were for things like major canal projects or overseas trading ventures. Let's say a canal would be a good idea somewhere, but the cost will be enormous. The only way to fund it is to have thousands of people pool their investments for it. Those thousands of people aren't going to be involved in running the project. Maybe they're just investing the equivalent of a hundred or a few thousand dollars today. But without limited liability, if the canal project goes under, every investor is fully responsible for the debts of that venture. You may invest only a thousand, but if the canal goes under before it finishes, without limited liability, you could be on the hook for many times your original investment. Limited liability allowed for the democratization of investment. Without it, only the rich are able to truly invest in things.

Historically, this was a huge barrier to investment and economic development. Rome for example didn't have anything like our modern finance system; most things were produced in large family businesses. You couldn't just go buy stock in a venture to invest in it. If you weren't willing to fund the entire thing, run the entire thing, and be responsible for the entire thing, you couldn't invest in it.

This is what corporations were meant to solve - the problem of funding large risky projects beyond the ability of single investors to reasonably afford. Historically, you couldn't just go and register a corporation on a whim. Often they required acts of legislative bodies to create them. They were seen as morally dubious in many ways - after all, shouldn't everyone be responsible for the consequences of their own actions? Limited liability gets away from this. The bargain was made that though limited liability sacrifices some amount of fairness and justice, the prosperity the projects it allows will produce will be worth it on net.

But that isn't how incorporation is used today. Today, landlords will open up dozens of LLCs. They'll put a single property into each LLC. If a tenant is seriously injured due to the landlord's neglect, the most they can ever sue the landlord for is the value of the property they rent. The landlord could own a hundred properties - the most you can ever sue them for is the one you're renting. In a serious injury, you could be on the hook for millions in lifelong medical expenses, and your landlord may be sitting on a fortune of a hundred million of dollars, but you can only ever sue them for the few hundred thousand the property you rent is worth. The company you're renting from doesn't own any more assets than that.

Rent seeking is not the type of risky moonshot venture that incorporation was invented for. Incorporation for landlords is not about encouraging moonshot investments, it's just a state subsidy for landlords. It's not like we wouldn't have rental units without incorporation. Most of the citizens of Rome rented. The concept of renting is likely as old as the concept of a city. The rental market worked just fine without limited liability.

This type of liability risk should not be handled as a subsidy by the state. Landlords can already purchase liability insurance. And that's how they should have to handle all the risks of being sued by their tenants. Someone with a dozen rental units can get a $5 million liability policy if they don't want to put their entire net worth on the line in the event one of their tenants being seriously hurt.

And crucially, such a system would much better protect tenants. We currently just give the subsidy of limited liability to landlords as a gift. We ask for nothing in return. Insurance companies aren't so generous. If you want a liability policy for your rental units, the insurance company is going to want to have a say in how those units are operated and maintained. The insurance company doesn't want to insure a dilapidated death trap of a rental house.

I don't think landlords should be able to put rental houses into LLCs, because I think we've completely lost the plot on what corporations were meant to achieve. Hell, I would set the minimum number of owners for a corporation to be a hundred people (with limits on how much a single individual can own.) Incorporation was meant as a tool for crowd-sourcing daring and groundbreaking infrastructure, research, and other ventures. It was never intended to be a gift to rich people operating ordinary businesses that they have complete individual control and ownership over.