Yeah I'm hoping they just sped that up for demo purposes, but if not it shouldn't be too difficult to change. I can see why they have, for simplicity of game plays sake, few people are going to enjoy having to meticulously pull apart an entire house.
What I would prefer was if at least parts of the house were left standing, because obviously some parts are going to be unusable, although that seems as if it would be a bit of hassle.
Or you can take down a house bit by bit, like making a rough square in the wall. So it not only looks like you are realistically taking down a house, you could also make a window to snipe some enemies.