Who does this intrusion NOT effect?
Those who cannot afford to or who choose not to travel by air.
This is not about security, it is about making the air-traveling segment of the productive class feel oppressed and invaded by government. It is meant to make us used to the feeling of not being in control of our privacy and personal space, and that it must be ceded to government upon demand.
Like John Roberts, this is a gift from George W. Bush.