What if somebody is a brilliant theoretician but they easily lose focus when people nearby do distracting things? Still a weak-minded, unmotivated individual?
Um, yeah. Of course, back then, a tight sweater would have been a hell of a lot more distracting than a laptop screen saver.
If you easily lose focus, that's your issue. Learn to concentrate. Banning laptops won't take care of your problem anyway. Lectures don't all take place in dark, windowless rooms -- something distracting will always happen.