Obviously you were not a math major. If you're studying upper division math courses or other stem fields at a major research university, the pace of courses is such that it is expected that a student should spend something like 15 hours per week on one such course outside of class time (So taking more than two such courses during one semester is basically a suicide for most students). If you fall behind the lecture material by more than a week, chances are good that you're going to fail. Because of the pace of the course, there are weekly homeworks, the homeworks are often worth 50% of the final grade to encourage students to keep up with pace. By the way, group work is almost always encouraged because many problems are freaking hard to solve alone. I am not talking about first or third semester calculus courses with BS homeworks that have the numerical answers posted on the back of the book, but formal prof-oriented courses like Real Analysis, Abstract Algebra, etc.
If homeworks are nit going to be graded any more, the way I see it, more students are going to fail advanced STEM courses unless the they're going to get seriously dumbed down.