Being a landlord is not hoarding. Taking a risk on a buying a property, and maintaining it, is not hoarding. There are bad landlords and good landlords, and yes, with the levels of supply and demand how they are, it's easier to be a bad landlord. But the answer isn't "get rid of landlords". It's "vote out the people causing this situation."

Except people don't require onions to live, whereas shelter... Also, if the onions stayed intact for 100 years, a group of onion lords taking advantage of widespread capital failures could simply hoard onions near-indefinitly, and there would be no "real" shortage, but the market would have a "shortage". This is exactly what is happening in world real estate.