If you build anything, then remove the platform, building, or conveyor pole that was underneath it, the above building will continue to magically float and function.
This could lead to serious exploits. A floating factory would be immune to attacks, should you add monster aggression in the future. You are also able to create unintended conveyor connections and object placement.
I know some people like this and consider it a 'feature,' but it seems like an exploit/cheat to me. I think it would be in the best interest of the game to fix this, my suggestion being making it so that you cannot deconstruct something with another object on top of it.