Imagine how much more work it is to try to solve these exercises then. Exponentially more than creating solutions for someone who already mastered this topic. This tells me a lot about how a teacher thinks of students.
It comes from experience. I had several professors who did not even release the script for a course, much less the problems and never solutions - everything had to be written down by hand by students while you were supposed to listen, understand, and ask questions. If you couldn't read something or were too slow, you could not study this part.
