I'm not sure whether this is intentional or not with the stability issues and all, but I can't help but think all buildings should spawn -some- kind of loot, but when it comes to houses only like 40% of them ever spawns loot. Other houses just don't spawn everything ever.
Yes I know about the item clipping-in-the-floor issues. And I've checked the houses countless times ever since I started playing, both regularily and even right after server resets. A lot of houses just don't spawn -any- kind of loot -ever-. Not to mention structures like shacks or Deer Stands.