-IMO a lot depends on the field. Generally, grading for liberal arts areas are higher than for STEM areas.
When I was attending Cornell, the cutoff GPA for Dean’s list in the College of Arts & Sciences was higher than the GPA cutoff at the engineering school. One can infer that the engineering college graded tougher.
re #3:
-While Cornell is tough, it is not necessarily tougher than other schools with comparable student capabilities, in comparable fields of study. There have been posts to the Cornell subforum, by students who transferred from one school to Cornell, (or their parents) that the first school listed in #1 was harder than that student found Cornell to be. A student at the second school found it to be essentially the same level of academic demands. Cornell has relatively a high proportion of STEM-related majors, which probably impacts the aggregate GPA. That does not necessarily mean a history major there has it tougher than at a lot of other good schools.
- The problem at a university with students who have many areas of excellence is that one person's throw-away class that they took for it to be easy is another person's passion, and central to that other person's interests and abilities. A lot of STEM majors should not expect highest grades in a writing-oriented liberal arts seminar class stocked with students like my daughter- a liberal arts major who basically writes for a living. That is in her wheelhouse, and she is just better at it. When I attended I took a similar freshman seminar and got a B range grade too. At one point the prof read aloud the paper of a student who received an "A". I always fancied myself to be a strong writer, but this person's paper was far beyond what I was producing.
But this kind of situation is not unique to Cornel, it would happen at any school that has strong students across the board and also has distribution requirements.