I wouldn't want to trust 3/4 of the TSA folks I've encountered to run a cat house let alone exercise their independent judgement when it came to my safety or the safety of my friends and family getting on an airplane. While this isn't very polite, this screwup pretty clearly indicates that the TSA isn't exactly made up of "A-players."
Like most people pontificating/bitching about the TSA I of course have zero legit expertise in airport security, but I do have a bit of first hand experience at Ben Gurion airport in Israel where the threat level is generally pretty high.
The first thing you notice is that the security people always look like they are playing on game day. Unlike joe-blow TSA agent, these folks are alert, speak multiple languages, and likely get some specialized training to detect if someone is lying or was tricked/coerced into carrying a bomb.
It's weird-- the vibe is at times both more tense and also more relaxed than an American airport. The security people at Ben Gurion seem less like bureaucrats following procedures and more like smart people empowered to exercise their judgement (ex grandma isn't getting yanked out of line.)
Once you're in, you get asked some almost chit-chatty questions about what you're up to while they review your travel documents but the whole time it also feels like you're talking to an observant doctor or physician examining you for symptoms of an illness. If you "pass" their filter you're done & on your way in quite literally a minute or two (and it being Israel there's naturally some controversy about who gets selected for "extra" scrutiny and why.)
I've read that the problem in the US is that it's too big to cost-effectively implement a system like this everywhere and that's probably true. But maybe at least at the big/major airports there ought to be some equivalent specially-trained "hunters" who know their stuff.
It's a good thing that the agency head resigned because the TSA flunked a practice test instead of the real thing.