It's also common to overlook that just because there is a house already bought, doesn't mean people can live in perpetually without someone having to spend money. Houses require constant maintenance. Floors won't clean themselves, plumbing won't fix itself when it breaks, etc. Even if people had alternative food and water sources, you can't house them in comfortable conditions without expending money on maintaining those conditions.
He isn't. The tax payers are.
Of course, the tax payers are showing up and feeding everyone and staffing the place. So it's free money, right? No work involved at all. Not like he's doing a ton of work and creating value, then charging for it...or anything.
Until they aren't, at which point the building is still a liability even if it is empty.