One thing's certain. The U.S. Government wasted billions of taxpayer money training TSA agents--often recruited from ads on pizza boxes--in useless behavior analysis techniques.
You want to see useless security theater, go to China. Every building has a live-on-site guard who's entirely unable to detect or prevent thefts, won't intervene in a fight, or do anything other than lock the doors at night. Some of them wear military style clothes and have prominently displayed riot gear (shields and sticks), despite being clearly too frail to actually hold back anybody determined. Train stations x-ray your bags, not just for going to the train but also for access to the ticket office. They don't notice/care if you go through with kitchen knives in your bag, despite the recent terrorist attack that was done using knives. You can sometimes bypass the X-ray by just walking past and refusing to put you bag in it too! A Beijing train station has a podium outside with a soldier standing on it holding a stick. Not sure what that's for.
If you view TSA not as an organization designed to prevent attacks, but rather as an employment (employes people who would be flipping burgers instead) and contracting agency (provides billions of dollars for security companies who design "behavioral techniques" or make machines called "Rapiscan") then you see as a very successful agency.