Sure, which is why you tell people to turn the device off and only when that completely fails do you take greater corrective action.

I do think we overreact on security matters, but I do think it's reasonable to not head over the Atlantic with something labelled "BOMB" if you can't figure it out.

I think if you set the amount of security to zero you'd get more bombings. Before 1990 we had a 2-3 per decade. This may not sound like much, but given that we have about 0-0.5 airliner crashes with fatality per year, it would be a significant contribution.