The course is meant to teach students how to write numerical code (integration, PDEs, Monte Carlo, …) rather than to teach OO design itself. C++ is the chosen vehicle, and the professor has a strong OOP background, so the course material ends up structured that way.
That’s why some of us wonder whether a lighter approach (lambdas, NumPy in Python, etc.) might let students focus more directly on the numerical methods without so much boilerplate.
Using C++ as a pedagogical tool for general teaching of such methods would be quite a choice.