That is very rude. They could at least email or call and say they found another solution or want to postpone indefinitely.
I always wonder what kind of person could just not show up and have the courtesy to cancel ahead. It has only happened to me once and I was just glad that I never even got to the interview because that kind of selfish person is not the type I would want in my daycare. It is obviously very inconsiderate of your time because you prepare and wait and then - nada. Pfft