Sorry for the thread necro'ing here, but
YES
For me personally this is the logic I'd like in a game like this:
if the block is anything not solid (e.g. dirt), and there is open space below, fall down
if the block is anything solid (e.g. rock, wood, etc), and there is no adjecent block, and there is open space below, fall down
basically if you want to create a house the roof has to be something solid. dirt will just fall down on your head, and nothing can float in the air
looking into modding to fix this, myself