It’s simply human nature. Teachers can either lie to themselves and you about it or mitigate it. What more could you possible want from them as humans?
I somewhat assumed there would be commenters suggesting the human angle as a retort. That's why I prefaced with both "this is what the teacher expects of me" and "understanding that educational staff is already often overworked." It just seems to me that the current systems aren't sufficient, and acknowledging that is what leads people to improving those systems. The above commentor suggested what they do in academia as workarounds to what the study showed, and I'm saying even that is not sufficient.
It seems like you're agreeing with me, but jumping to their defense with "people are fallible." People are fallible, that's why we build systems to take human elements out of it. Recognizing where humanity has soured something is key to that.