Co-incidentally, just heard an interview on the radio with a very articulate and amazingly calm Italian journalist (think his name was Bertolotti) who survived the runway crash and fire in Yogyakarta in Indonesia. His comments underline the importance of watching the demo. He also said that he always does watch it, out of politeness, even though he flies a lot. "It isn't nice to have the radio on, and no-one listening to it!"
It's strange, because in all the discussions about lack of attention to the safety demo, I've never heard this point -- the matter of simple courtesy -- raised before.