Gentlemen,
I would think that on almost every flight today there are several passengers (and pilots

) "forgetting" to switch off their mobile, Ipad, laptop etc. So I suppose that if the dangers were that big, some
real proof about adverse effect on the safety of flights would have appeared by now if there were any.
But I agree that switching these devices off harms nobody and therefore switching them off is a good idea, but please don't dramatize...