I disagree. In my personal experience. Dishwashers work better when they are well packed rather than well spaced. Important emphasize on "well packed". Obviously the water needs to be able to flow between the items and not get puddle on top of a bowl or cup. The dishwasher presented here is well packed and it will wash very well.
Half empty dishwasher will probably not be an issue and things will come out clean, but it's a little wasteful.