It's a "weed out" class. When a huge number of people want to be STEM, but there is no way they're going to last, it's better to have a tough class that sets that expectation early, so they have time to pursue a more achievable major. In my case, huge State university, Freshman year Physics was the weed-out class. It was not advanced or (to me) particularly difficult, but there was a LOT of content, we moved very fast, and the workload was punishing. If I recall correctly, our first class was over 1000 people in a huge auditorium forum. By the time we took final exams, we were down to around 100 people.