> They don't stop hijackings (locking the cockpit door does that)
9/11 also stopped all future hijackings. Up to that point passengers were trained that if they stayed calm they would likely survive. Now? Short of the hijackers getting guns on the plane, passengers will absolutely fight back.
> they don't stop bombings (there are much better targets for that, which don't involve killing the bomber)
Suicide bombers are probably the main vector that TSA helps avoid even if they miss some items sometimes.
> Now? Short of the hijackers getting guns on the plane, passengers will absolutely fight back.
I'm not even sure guns would hold some wannabe heroes back.
> Suicide bombers are probably the main vector that TSA helps avoid even if they miss some items sometimes.
Not really, but this is because there are pretty much no suicide bombers anywhere in airports. They are incredibly rare.
But if you're a suicide bomber, by the time you get to the TSA checkpoint you can do a ton of damage inside a terminal during a holiday season when all airports are packed. Until then no one is stopping you.