Imagine compulsory education in times where it is impolite or improper to tell students why the education or a subject is required. Saying why and explaining the why is approximately correct is way to allow some room for thought or to leave some question unanswered. College level instruction in the US and Canada assumes very little or writes off the knowledge of mathematics attained by most students at the high school. There are some good high schools, but they do not produce most college student. Mathematics courses in high school should not be compulsory wherever mathematically trained and adept instructors are not available.
Students get no benefit from a compulsory course taught by a math-shy teacher.
As an instructor in a US College, in a remedial algebra class, I met one gym teacher whose job in high school was to teach algebra. His alternative was unemployment. As an instructor in the same college, I met prospective high school mathematics teachers for whom calculus was too hard. Speaking to present-day college instructors in mathematics points to the presence of education students afraid of mathematics, but attracted to high school teaching due to the reported shortage of instructors in this field. The lessons at this website, easily understood and repeated might help prospective and practicing teachers, math-shy or adept, be better or excellent teachers.