“This is mainly due to the curriculum being easier and the grading is more lenient.”
Look at my new thread.
There were 2x as many CSE grads with Summa Cum Laude than IOE grads. IOE grading is not as lenient as you think.
Furthermore, operations research can be quite complicated. It is the instructors, not the material itself, that may make classes “easy.” For instance, “easier” linear programming models are used in the undergraduate classes. If the instructors wanted to, they could easily choose more complicated models.