If you were paying attention back when the TSA started telling people to take their shoes off, it wasn't because of the Shoe Bomber incident, which hadn't happened yet. It was because a lot of mens' shoes have metal shanks in them and were setting off the metal detectors, and they didn't want the lines getting held up sending people back to run their shoes through the X-Ray machine.
At first it was a "Please take off your shoes" request, but if you knew you had non-metallic shoes they didn't force you to take them off (I tended to wear Teva sandals, and lots of people in Hawaii wear flipflops, especially inter-island.) Or sometimes they'd yell at you for not doing it, and they really dislike being challenged by anyone, such as being told "If it were actually a TSA rule, it'd be on the sign", which often got me an honest response of "we can take you in the back room and search through all your stuff long enough that you'll miss your flight, so obey orders or we'll do that."
Then a few airports started saying "Everybody must take your shoes off, it's ALWAYS been the rule", because it's easier to have the grunts think it's always been the rule than have them actually have to think or do different things for different people (and realistically, a lot of travellers don't realize they have metal in their shoes, and sometimes there's just a bit of metal like shoelace hole reinforcers in sneakers, so it only sets it off if the metal detectors are turned up high and not if they're set lower.)
Then the shoe-bomber idiot did his thing, and after that the TSA started making everybody take off their shoes, and then they started making videos for people to watch when they're stuck in unreasonably long lines, which dishonestly tell people that the shoe rule was made for our safety.