On the surface, it makes no sense whatsoever that a pilot, the person who controls the plane and the fate of everyone's life aboard - cannot be trusted to carry a firearm. Trusted to fly a large machine with many people on it, but not to handle a small, simple device?
But it makes perfect sense as it isn't about trust, nor common sense, nor safety, nor security. It is about the abolition of firearms from civilians. Plain and simple, it is the anti-gun fanatics taking the fight to gun owners and gun users anywhere they can. And that includes pilots who want to carry.
Sadly, they have allies in government. As the concept of self-defense is inherently an individualistic concept, and ultimately undermines the collectivist, governmental concept of "we're here to protect you" ...Instances, examples, and actual practice of individual self-defense using a firearm is extremely damaging to the government control freaks and gun control fanatics. It proves them wrong. And when they are wrong, their agenda is harmed. And when their agenda is harmed, money is at stake.
For those people who are both sane and practical, arming pilots is the easiest, most cost-effective and most effective method of security air travel. An armed pilot cannot defend from a bomb - airport security is still needed for that, but an armed pilot along with a reinforced cockpit door can defend against hijack. Eliminating the possibility of another 9/11 type event.
That's right, a $500 handgun in each plane would have been enough to prevent 9/11 from happening.
That drives a stake through the heart of the gun control extremists and their arguments. Therefore, they attack it at all costs. The worst cost of all being the safety and security of Americans.