I majored in math & physics, not CS, but was aware of the CS coursework at the time, 30+ years ago. Back in the day, the exams were more or less designed around the problems in the textbook. You could set yourself up pretty well for the exams by working the problems over and over. (Mostly derivations in physics, with or without numerical results, or proofs in math). Doing so would commit the factual content (e.g., formulas, definitions) to memory and get you quick enough in the mechanics to have some spare time during the exam for dealing with the unexpected.
What you learned in class was, among other things, the style of communicating results, i.e., what a well written derivation looks like. I imagine that a CS course could be structured in this way, if a program in CS is analogous to a proof in math. Whether it's actually a good way of teaching is anybody's guess, but it's how things typically worked.
The students who thought that they were expected to mimic the "tricks" and opinions of the professor, were suspected of simply not grasping the material. On the other hand, though I grasped the formula for getting good grades, nobody ever told us that formula, and a student who never guessed it, would be faced with nothing but frustration and sorrow.
When I taught college math and engineering for a brief period, many years later, I told my students the trick, on the first day of class.
Of course I have no idea if this was a good preparation for the workforce, but I'm pretty sure students were expected to combine their textbook learning with experiences gained outside of the classroom, e.g., from research projects, internships, etc.