From what I understand reading the course outline, this is an introductory class. Foundational material in a subject is often "completely disconnected" from the reality of the discipline. If I was an engineer taking a first course in integral calculus, should I worry that my teacher may not be a seasoned practitioner, or should I worry that they are good at getting me to understand the fundamentals? I can definitely see your argument if this was a professional practice class, or something vocational, but it's a 100 level CS class.

I think you should worry. One of my math professors taught us how factoring to a(x+b(x+c*(...))) is a great optimization in an introductory class, because he had no idea about CPU pipelines for example.

Horner’s method for polynomial evaluation is used because of numerical stability, not speed.

Could you elaborate?

I'm working on a project where the evaluation of a 4th degree polynomial is on the hot path. My micro benchmark (evaluating two polynomials + little bit of addition) shows that using simple Horner's rule is already somewhat faster, and implementing Horner's rule with fused-mul-add is more than twice as fast.