I know a few teachers, the "cringy and bad" is the goal, not a mistake. It's apparently quite therapeutic watching the "cool kids" squirm. How bad can you make them, but not make it obvious what you're doing?
The fact that it also helps a lot of kids remember it is almost just a bonus.
I've got a friend who was slightly too old when the word yeet became popular. He decided he would use it confidently, often, and incorrect. He still does.
He's excited to embarrass his kids by doing that with whatever the current slang is when they are 12 or 13.
There is a psychology to using cringy memes. Can't use them all the the time, and you need to fit the right cringe into the right place, but when you hit it, it does tend to make them remember a point they might not have.
Much of teaching a classroom full of kids effectively involves a perverse mix of psychological warfare, manipulation, and entertainment. You should try it some time.
Omg there was a teacher at my school that would make songs that were just some super basic beat and him conjugating verbs, with a little bit of echo. Then he'd play them during class while looking at the students.
My speculation is that teenagers react so vile to adults trying to fit in partially as a unwittingly defensive mechanism. Teenagers have some social skills, but not all and thus having separate youth culture provides spaces for learning - adults trying to fit in are possible OP in those spaces and keeping out adults altogether might help with abuse prevention as well.
I don't really know how to test or research this speculation though.