I flew for a couple of years and I agree with you. It is silly. However, it is an FAR and we never knew if there were an FAA inspector on board giving us a check ride. They would watch for specific things, including seat backs, carry-on luggage, emergency exit row briefing, and safety anouncements. I work for an airline and don't make enough to pay a $10,000 fine so I was very anal about it too.