TP455, the issue for me is who is responsible for the use of a weapon. The Guardsman is responsible to his military superiors for any use of his weapon; the pilot, as far as I can see, to nobody.
As a pax, I can tolerate being in the vicinity of weapons wielded by a properly constituted and trained (and, of course, friendly to me ;-)) military or police force: I am not comfortable being in the vicinity of weapons wielded by those who, in the last analysis, are answerable only to themselves.
I am missing the logic here..........You trust my judgement to fly you and your family in the back of my airplane in weather that you wouldn't drive a car in, but somehow my judgement would be impaired in the presence of a firearm because I am not answerable to some higher authority??? As soon as the cabin door is closed, I (as PIC) am responsible for all that happens in my aircraft (until Mr. Terrorist decides to take it from me, at which point I will be dead, so then HE is responsible).
Since it has been proven that the airplane itself can effectively be used as a weapon, why is it OK for me to fly one since I am answerable to only myself (!)?
BTW, I am not comfortable knowing that the only recourse available to me in the case of a hijacking (however remote the possibility) is the aforementioned future new hire in the F-15!