Assuming a real threat a ban on those items being carried on board does not address lethal stuff in the belly of the plane. Look at Lockerbie.

I still think the day will/should come when passengers and their belongings will fly in separate planes. I can imagine the chaos while the logistics of reunion are being determined and enacted but that single act would remove almost all of the opportunity and all of the motivation. No terrorist organization is going to brag about blowing up luggage.