To understand what makes these measures so absurd, we first need to revisit the morning of September 11th, and grasp exactly what it was the 19 hijackers so easily took advantage of. Conventional wisdom says the terrorists exploited a weakness in airport security by smuggling aboard box-cutters. What they actually exploited was a weakness in our mindset — a set of presumptions based on the decades-long track record of hijackings.
In years past, a takeover meant hostage negotiations and standoffs; crews were trained in the concept of "passive resistance." All of that changed forever the instant American Airlines Flight 11 collided with the north tower. What weapons the 19 men possessed mattered little; the success of their plan relied fundamentally on the element of surprise. And in this respect, their scheme was all but guaranteed not to fail.
For several reasons — particularly the awareness of passengers and crew — just the opposite is true today. Any hijacker would face a planeload of angry and frightened people ready to fight back. Say what you want of terrorists, they cannot afford to waste time and resources on schemes with a high probability of failure. And thus the September 11th template is all but useless to potential hijackers.
How we got to this point is an interesting study in reactionary politics, fear-mongering and a disconcerting willingness of the American public to accept almost anything in the name of "security." Conned and frightened, our nation demands not actual security, but security spectacle. And although a reasonable percentage of passengers, along with most security experts, would concur such theater serves no useful purpose, there has been surprisingly little outrage. In that regard, maybe we've gotten exactly the system we deserve.