The most trivial example, the requirement for assessment will put a load onto the course staff. While a correct answer presented in the conventional way is a typically easy to assess, an incorrect answer or an answer presented in a non-conventional way is much more difficult to assess.
The people I worked with typically wanted to see students succeed. It went well beyond the mechanics of delivering instruction and assessing work. They considered what they were doing and put time into modifying their practices when students did not appear to be engaged. For a handful of students, it would be successful. In the vast majority of students, it would flop since the disinterested ones were rarely receptive. Some cases may have been similar to yours, where it sounds like you were focusing on other subjects. Some students appeared to be, ahem, more interested in the non-academic merits of university life. It is difficult to tell what the breakdown is since those students were always the most distant. But either way those passive students were a drain. They simply weren't as much of a drain as the cheaters.
Most of what people learn is from the day-to-day, not what they are actually studying. What does that tell you? Instead of ad hominem for 'non-academic merits of university life' perhaps they are not in fact being instructed properly. This makes sense because graduate school is such a grind for personal research instead of actually educating other people.
Teachers need to design their programs around actual learning principles like: Deep Processing, Chunking, Building Associations, Dual Coding, Deliberate Practice.
The people I worked with typically wanted to see students succeed. It went well beyond the mechanics of delivering instruction and assessing work. They considered what they were doing and put time into modifying their practices when students did not appear to be engaged. For a handful of students, it would be successful. In the vast majority of students, it would flop since the disinterested ones were rarely receptive. Some cases may have been similar to yours, where it sounds like you were focusing on other subjects. Some students appeared to be, ahem, more interested in the non-academic merits of university life. It is difficult to tell what the breakdown is since those students were always the most distant. But either way those passive students were a drain. They simply weren't as much of a drain as the cheaters.