I agree with this sentiment. The inconvenince is small compared to the potential safety issue. I do think those with such allergies should make the airline aware of this when making reservations so appropriate measures can be taken BEFORE everyone is boarding.

That said, if those with severe peanut allergies can die from airborne exposure, doesn't it seem like an incredible risk to get on a plane in the first place? Even if you ask the passengers not to open any peanuts and they comply, what about the guy who brought on food that has peanut oil in it - fried snack food, some pasteries, and many prepared asian foods contain peanut oil. Many people may be unknowingly bringing these foods on. As someone else mentioned, the seats, floors, and seat pockets almost certainly have peanut dust on them.