Before jumping to conclusions, maybe ask for context too? In particular, this was a high school for gifted math kids, and what I learned through regular classes let me pass math uni entrance exam in the top 10 (out of ~500 students) with no extra prep and even easily pass a couple of semesters of uni math with almost no prep (I took exams for two semesters after the first semester). My (lack of) working habits did catch up to me after that.
Also, for 4 years in two uni degrees, I did not get such a good teacher ever again, and there were a few who were easy to get great grades with.
Perhaps you can give some benefit of the doubt, though?
Sometimes a teacher can also do a great job of getting you interested (also important) but I was focusing on quality instruction.
“Anyone who applies the smallest amount of effort gets a B and anyone who really tries gets an A” is a path to being seen as a great teacher in the eyes of the students, especially the students who got a B.
I've responded to them directly what that got me (like great uni entry exam scores with literally zero prep for a maths program, and a couple of semesters of exam passing with minimal prep for a maths/CS/physics majors).
On top of that, I am talking of this almost 30 years later — perhaps I have some perspective and I am not a fresh out of school guy who just loves getting off the hook easy?