I think it's because of the space saving. We park our cars in front of the garage, and wouldn't have enough space on our driveway to allow for the door to swing

I think it's because of the space saving. We park our cars in front of the garage, and wouldn't have enough space on our driveway to allow for the door to swing out and not hit a car parked there. Also most garage doors aren't see-through, so you may not know if a car is parked there at all, leading to a high number of fender dings.