Regardless of whether or not electronic devices interfere with the electronics, each different model would have to be tested against it to be approved. That being said, electronic devices do create a distraction. A distraction which could hinder progress in case of emergency egress. This is how I've explained it to my pax when asked and no one has had a problem with it. Even without the distraction, I have witnessed grown adults with no other visible impairments struggle and sometimes need help fastening/unfastening their seat belts. It's a sign of the inattentiveness of the general public these days.