People keep pointing out to you that passengers were in fact using their phones to record footage of the interior of the plane (eg to let their friends/relatives know what was going on in case they didn't make it). Of course people are easily distracted by phones when they should be paying attention to other things, but virtually all people already in an emergency situation are fully present unless they're injured or caring for an injured person. I think you're underestimating people's ability to multitask when they know it matters.