I get so frustrated and annoyed by those who play with their electronic toys on flights in the pre-takeoff, pre-and-post-landing phase.
The primary reason for the rule is one of safety. But there's another aspect - crowd control. When you're in a tight cabin with no legroom and the plane is going nowhere then EVERYBODY is going to be frustrated. Mix that in with tsk tsk tsk or beep beep beep and you're going to push some people over the edge.
Alec Baldwin would be on the end of my fist if I cross his path. Unless he has an electrical engineering degree, like me, or is an experienced aeronautics designer or pilot, then he has no place determining what is and isn't safe as far as use of electronic devices on a flight.
People are idiots. The number of people smoking a cigarette with the window down as they drive into the local Tesco fuel station really bothers me.