Forget the radio interference, put hard projectiles like laptops and tablets away during take-off and landings so they don't go flying around the cabin if there is an incident.
And the government is what? shy? or embarrassed to admit such physics facts? But in turn had to make up lies and fake convoluted reasons to accomplish this?
You are basically implying that they all gathered in a dark room someplace at FAA and decided "Aha, we don't want all these projectiles flying around, but we don't want to reveal our true motives, so we'll ... call it electronic interference and tell them to stow away electronic devices, but now, everyone must keep this secret!", then they all raise their right hand, swear on their mother's grave, and there you have it, a new FAA rule.