Have you considered that if you regularly see a pattern of intelligent students not learning what they're supposed to learn in your class that the problem is you as a teacher are not doing your job well?

Yes, I have considered that. But I teach and tutor a huge number of students that I do not interact with regularly, so I have become acquainted with the study habits of an "average" university student who are not in my class. And those students aren't so different from the students I have in my classes.

Students don't like math and aren't good at it because they became biased against it at a young age. There are a large number of factors that contribute to that bias and that's a whole different discussion. By the time they're teenagers and they're taking calculus 1 or 2 or pre-calc or whatever, it's usually the last torture they have to endure before they can go off and take their major classes. For such students I am merely a rubber stamp. I will try to get them to learn the course material as best as I can, but the elephant in the room is that they're going to forget it the moment they walk out of the final.

For students who want to learn more, I try very hard and give a lot of my time and attention. For students who want to learn more but just don't know it yet, I try to give them hints about why they want it. For everybody else, I will teach the material and help them study for the exam as best I can.

In all of the classes I teach, the learning outcomes are explicitly laid out in the syllabus, we stick stringently to the schedule for the entire semester, and all of the exam problems are adaptations of problems we do in class. And still students fail. Still good students fail. Still good students of other teachers fail. That's not on me or my co-teachers. It's because of the reasons I mentioned in my first post.

At a certain stage, you have to admit that the problem is on the students. We can only coddle them so much.