If rudabaga owns his brownstone in Manhattan, he has nothing to worry about. Limited supply and endless demand will keep his house nice and high in price.
What you say is probably true. However, if there is a serious attack made on one of our big cities, one with tens of thousands casualties, the endless demand could quickly dry up.
Please Note: In no way am I wishing for such an attack. But I certainly won't rule out the possibility after 9-11.