No, there will never be another hijacking in the USA. The passengers of the plane will immediately tear any person attempting another hijacking to pieces. Any future hijacking attempt will be immediately understood as a mutual suicide pact by all passengers, and they will act accordingly.
This is why all airport security is completely unnecessary. Let nature take its course.
Can't do that. It would teach the public that they can control their fate, and make government less necessary.
Government has a vested interest in a docile population.