I think this speaks to something in the OP that bothered me:
So much of the student-hostile elements of teaching come down to manufacturing efficient metrics for learning. They don't guard past solutions because they don't want you to study from them, but because they need to be able to report whether or not you learned the material, and writing an appropriate test question, especially at higher levels, is hard.
Likewise, you didn't view office hours as a tool to learn the material, it was a tool to game the metric they force on you to determine if you're learning in the first place.
Its very easy for the execution of modern education theory to slip into an ouroboros of perverse incentives.
So much of the student-hostile elements of teaching come down to manufacturing efficient metrics for learning. They don't guard past solutions because they don't want you to study from them, but because they need to be able to report whether or not you learned the material, and writing an appropriate test question, especially at higher levels, is hard.
Likewise, you didn't view office hours as a tool to learn the material, it was a tool to game the metric they force on you to determine if you're learning in the first place.
Its very easy for the execution of modern education theory to slip into an ouroboros of perverse incentives.