Looking at this in a saftey perspective for passengers it makes alot of sense to post these saftey notices on the seats.
Like ,Who actually dose read the saftey notices? my guess not many.
Whilst having nothing else to do after already having read the magazine you bought in the airport shop three times over aswell as the boring inflight mag what else to do than to let your head wander around and start reading something else besides the no smoking sign in the toilets.
Might educate us passengers in what to do if something did happen to occur.