We seem to be conflating two problems under the label of no-showing. Cancelling without adequate notice, while still a problem for programs, is understandable in some circumstances. If you realize 10 days before an interview, perhaps because of a really great interview somewhere else, that you are no longer interested in a program, I would think the sensible thing to do is to politely cancel, despite the fact that the program may have trouble filling your interview slot. If you knew earlier and waited to notify them, shame on you.
An actual no-show, where you don't even notify the PC, is rarely justifiable. The only thing I think would excuse it is a sudden calamity, such as the unexpected death of a close family member. Even then you should send a quick email if you think of it, but the oversight should not be held against you.