From teaching a little CS and numerical computing in college and now teaching programming, I agree with you. Too many students come out of high school without the ability to manipulate mysterious symbols without any real understanding of what they mean. Some students only know how to follow scripts to solve a problem from a template. Others need a concrete understanding before engaging with the abstraction, so they can't explore the math in order to gain an understanding. Maybe that's what he was trying to get at with "following obscure steps".
High school teachers, please make your students manipulate mysterious symbols more.
High school teachers, please make your students manipulate mysterious symbols more.