Things have changed. Back before 9/11 passengers all understood that when hijacked, they should sit tight, don't give the hijackers any trouble, and they will come out of it alright. 9/11 changed all that. Now passengers all understand that if they let the hijackers take control of the aircraft, they will die a fiery death in the crash. Since then, a few "unruly" passengers have been subdued in flight by fellow passengers. In one case a fire axe was used as a pacifier.
If we just let the passengers carry heat, then Abdul the Hijacker has to worry about some little old lady passenger in economy taking a .38 out of her purse and splattering his brains all over the cabin ceiling. And certainly hijackers armed with box cutters aren't going to win over passengers with handguns. And if we say handguns are OK, then TSA can stop hassling passengers over the odd Swiss Army knife in some guy's pocket. And we can drop that stuff about liquid explosives. The liquid explosive is so touchy that Abdul the Hijacker is more likely to have the stuff go off in the taxi on the way to the airport than in flight. Real terrorists use Semtex, a plastic explosive.
If one in twenty passengers carries, then the hijackers will face a fusillade from five to ten armed passengers no matter what flight they try.
And we could solve the long security line problem that TSA is putting us thru. For that matter we could lay off TSA and save our selves a lotta hassle and a lotta money.
All we need for decent security is to X-ray all the checked bags to keep the terrorists from putting a bomb in the baggage compartment. And X-ray the hand luggage as well. We could solve the long line problem overnight.