There currently does not exist any airport which is designed to accommodate humans. Every human that walks into an airport is assumed to be a terrorist, which implies that the design of an airport is based on that assumption. I would argue that approximately 99.9% of all humans are not terrorists, which means that 6.5 million people are terrorists, or have terrorist-type thoughts and plan to bring them to fruition.
An ideal airport would not have any security and would be designed like a movie theater. Customers buy tickets and then proceed to their appropriate aircraft. The process should take less than 15 minutes. This is not a laughable prospect, nor an impossible one. Just think of termites.
When your house is infested with termites, you don't say to yourself, "You know, I'm going to fight these termites. I don't want to exterminate them. I just want to fight them every day for many years and spend as much money as I possibly can." But that is precisely how the U.S. military wants to deal with terrorists. Scratch that. There is no "want" about it, that is how the U.S. military does things. As slowly and as expensively as possible. It is not a living organism, so the concept of want has no meaning. While it is constructed of humans, the military itself is not a human and thus erroneous anthropomorphic thoughts easily come to mind.
So this is why we still have terrorists on the planet. The U.S. military does not view them as the average homeowner views termites.