By the looks of it, the Japanese can build strong houses with bad foundations. Those houses were being washed away and they weren't even being broken apart.
but inb4AmericanInvetvention
Actually it's a function of how homes are built. Typical residential buildings are secured to the foundation by embedded j-bolts screwed into the sill plate (the bottom part of the wall). I don't know the exact physics behind it since I haven't really studied it, but I imagine moving flood waters would exert enough force on a wall to shear the entire house off the foundation. It's not an issue with the foundation, or rather, the foundation is part of the problem, but it's the construction method itself, not damage to the foundation.
I should also mention that this construction method is called light frame construction is extremely common the entire world over. It was invented in Chicago in the mid 1800s and became popular again after WWII (with some changes) and almost every home in the US to date is built this way.