Bingo. The fact that there isn't a viable threat is demonstrated (ok, not proven) by the fact that a large number of completely undefended obvious attack vector

Bingo. The fact that there isn't a viable threat is demonstrated (ok, not proven) by the fact that a large number of completely undefended obvious attack vectors pursuant to terrorist goals have not been abused over a very long time. At some point the damage by TSA surpassed the expected damage from the alleged threat.