6 semesters seems like... a lot? IIRC getting a math undergrad at my Uni didn't require that many classes of calc.

I think calc 1 and 2 are extremely valuable. The concept of rate of change is fundamental to so many things in life, and understanding "area under the curve" is essential to understanding how many ideas are communicated, including lots of graphs in physics, chemistry, and economics.

Beyond that I feel calculus starts getting into specific applications and is less generally applicable to the populace at large.