Does this mean that the TSA security theatre is working? Nah I doubt it. :)
Security doors on aircraft and better screening of passengers does work but not the half arsed invasive approach taken in the US.
Yes you do not want people on board with dangerous thingies. But there is that which is true for most people and then there is taking it to far. In a way the only serious hijacking you are likely to get now is one that is intent on crashing the aircraft.
Previously there were two main reasons; Escape (from the law or from political oppression)...fly to another country, or to achieve political goals (release these people or we start to kill the hostages)...land somewhere appropriate and start killing the passengers.