"By that logic, we should remove security at Fort Knox because it never gets robbed."
There are, however, active threats against Fort Knox -- we know people want to rob it and that they would given the chance. On the other hand, it is not clear that there are people who would attack airplanes were we to scale back the TSA's operations (particularly airport checkpoints).
> There are, however, active threats against Fort Knox -- we know people want to rob it
Fort Knox seems like a bad example of necessary security. How far would you get with a convoy of trucks, each carrying some tons of gold? Does that gold need more security than a nuclear weapon?
Fort Knox seems more like an example of security theater, designed to impress people with the idea that a pile of gold matters a whit compared to large modern nation's budget.
There are, however, active threats against Fort Knox -- we know people want to rob it and that they would given the chance. On the other hand, it is not clear that there are people who would attack airplanes were we to scale back the TSA's operations (particularly airport checkpoints).