Well that's not true. I live in a Soviet era house that had an entire second floor built on top of it. We've had to drill through the brick walls to replace the natural gas pipes with pipes that run outside the walls, we've had to dig under the foundation when we got connected to the city's sewer system (again, Soviet-built), and again when the main water pipe burst and threatened to wash out the foundation. If the load-bearing walls had been constructed to the same "it works" standard as the things we've had to fix, we wouldn't have a house anymore.