This morning, I faced a serious conundrum.

Dutchman said:
Still seems like a stupid rule, what is a terrorist going to do, follow the rule and stay in his seat instead of blowing up the plane?

*time to blow up the plane! - begins to stand
"I'm sorry sir, we are 29 minutes out of the airport, you can not get up"
*foiled again!, dasdardly americans!

Let's see. Terrorist stands up to do break down the cockpit door. Stewardess immediately contacts the captain to report it while another tries to convince the man to sit back down. While he refuses/knifes her, the captain has already alerted the authorities and is diverting his course away from the city while F-16s are scrambled to escort/force the plane down. Worst case, the pilot has steered the plane far enough away from the city's main targets that in the time it takes the hijacker to make his way towards the city, air defenses have time to track it down and blow it out of the air, preventing it from plunging through the dome of the capital. Moreover, since he is clearly in the wrong and standing up when he should not be, and refusing the orders of the crew to take his seat, he's clearly labeled himself as dangerous giving every passenger on the plane the opportunity to detain him in whatever manner necessary to save themselves from the possibility of being blown to smithereens.

Alternative: Every man, woman, and child on the plane scrambles to jump up and piss before the fasten seatbelt sign goes on, and in the scramble terrorist gets up and breaks into the cockpit. Suddenly he stands a lot better chance of getting the plane to crash through the dome of the Capitol than in scenario #1. By the time the passengers realize what's going on, they're watching F-16s flanking the jet and making desperate cell phone calls to their loved ones to say goodbye before becoming fodder for the nightly news.

Is it that hard to understand?

Moreover, is it that much of an inconvenience to you to have to lose 10 whole minutes of your piss-time on a flight? I'd think of all the security measures in place these days, this would be the last one you people would whine about.