The terrorists have boarded the aircraft with their kevlar and ceramic knives. They are more than a match for the plastic knives and forks carried by our passengers. The law-abiding Cabin Crew and the passsengers have been disarmed by security, since they are unlikely to be carrying ceramic nail clippers. The terrorists meet resistance from passengers. Some they will win some they lose.
Today the terrorists win. They now try to break down the fortified cockpit door. Today they succeed. If you are not armed with anything but bare hands you are going to die and your aircraft will be aimed at a suitable target. Your aircraft is then brought down with a sidewinder.
If the terrorist is lucky he hits a heavily populated target. Had you had a gun, you may not have saved your passengers but you may have kept control of your aircraft so that you could have landed it on a runway, saving a lot of lives on the ground.
To those of you who say you are not Police Officers, maybe so; but you expect your passengers and Cabin Crew to be experts in unarmed combat.
Put a gun on my flight deck. Let it be in a container which allows, if necessary, rapid disposal into the bowels of the aircraft. Draw up rules requiring a tech log entry whenever it is withdrawn from its holster and in such an event, let there be an enquiry conducted by the company