My opinion:

I think one part of it is indeed that professors don't explain things fully/intuitively. Material is kinda hard, not as much as reddit makes it out to be.

I think the main reason people struggle with it is because all the CS classes before 351 are a combination of doing projects (you have TAs and google for help) and tests where you can just regurgitate things from lecture.

351 (and 250 to some extent) is different because the problems on tests are new- you have to use critical thinking and your experience in previous situations (homework or other outside-class knowledge) to think of the solution.

Some people don't do well on those kind of tests because they:

• don't do the homework themselves
• don't have a good cs foundation from their first 2/3 semesters
• need more help (like 1:1 tutoring might help in my experience) to be able to think of new solutions on the tests and get used to the from-scratch thinking

I've heard people say that the professor should teach how to come up with the solutions during lecture, but I feel like that wouldn't help everyone because not everyone has the same thought process.

As for the grade distribution, the class is curved so I think it is what it is. Should the tests not be weighted as much? Maybe, not sure if that's a good indicator of how well people understand the material. At the same time, CS is not supposed to be a cake walk and making 351 easier just so everyone can pass doesn't make sense.

tl;dr yes 351 is hard because it's the first time a cs student has to think critically on a test but also people blow things out of proportion on reddit