They contributed value by giving a pile of money to the previous owner (part of the economy). Now they're recovering their investment. If they can't recover it in rent/resale, then why would they buy in the first place? Then where would the previous owner get their pile of money from? Ultimately it went back to the original developer who was smart enough to build a house in a good place that people in the future will want. Without that chain of incentives, he could just as well have built it in the desert. That's what I think the value is - incentivizing property development where it'll be needed in the future.