This isn't any different than running a business, except that landlords generally feel entitled to make a profit from their investment, no matter the economic situation, and laws generally favor that. Backing that is the army of folks like you who tend to side with the "small landlord", which normally leaves out that the vast majority of small landlords are quite wealthy, and tend to own multiple properties.

Yes, there are a small number of cases of a small landlord, with one property that they're having a hard time breaking even on, but those folks have a bad investment, and if they can't afford their investment, they should sell it to try to minimize their losses. Renters aren't on the hook to make them profitable.

By holding rental properties, they're inflating the value of homes for sale, making it harder for people to buy, and forcing people into renting.

We don't pity people who make stupid business decisions, so why should we pity landlords?

I never said we should pity them (I certainly don't) or that they are entitled to a profit. You're exactly right that they are running a business. They are running a business that comes with costs and risks. It can go right or wrong like any business. That's fine.

What I'm disputing is that it is necessarily exploitation and that owning your home is always the preferable choice.

I do understand where your sentiment comes from. The name "landlord" basically says it all. It hasn't always been a normal business and there is still quite a lot of that history left in the relationship between landlords and tenants (as well as in the grotesque distribution of land ownership in the UK).

About inflating the value of homes for sale I'm not sure. On one hand the available land is limited and so demand should inflate prices. I'm not even sure private ownership (or at least inheritance) of land should exist at all.

On the other hand, the price of homes as well as the level of rents is mostly determined by how many homes are built. More (private and public) capital flowing into building new homes makes home ownership and rents more affordable. Buy-to-let landlords provide some of that capital.

The other thing that could be done is changing planning rules and the taxation of land ownership so that more affordable homes get built.

I don't think home ownership deserves the status it has. Renting is fine. Affordability is far more important than who owns the place.

Renting is fine, but renting through private owners is something that makes the entire housing system more expensive so that a small few can profit.

There's lots of systems in which renting can be done through cooperative systems that doesn't involve leeches.

If you're taking a generalised anticapitalist view then I understand your position. But under the assumption that private capital exists, it is hard to argue that none of it should be used to increase the supply of homes. That doesn't preclude other sources of funding.

Also, it shouldn't be impossible to debate systemic issues without comparing people to pests.

My parents are retiring while renting and it's a hellish for them.