Because it's not that easy. I don't have 20K (or more) on hand to fix a building which went trough 150 years of life and lack of maintenance.
So why shouldn't you borrow the money or sell the property to someone who can properly take care of it?
This is what I'll do actually. I have no choice, and I'll do it ASAP in order to not loose too much money as the building state is devaluating as time passes.