I will argue against this for two reasons, both of which have to do with practicality.
First, education about these lending practices is likely to be wasted on students while they are in high school. For the majority of the students, the lending practices they would be taught about will not be relevant to them for some years to come. They are relatively unlikely to be able to remember the things that they have been taught 5 or 6 years later when they actually need those lessons.
Second, this sort of education would take away precious instructional time. In today's world of high stakes testing, there is not enough time in most high schools to teach even those subjects which are important for passing tests or for going on to college. The idea of taking up yet more time to teach a set of ideas that is not likely to be useful to the students (because they will forget it before it is relevant to them) is not a good one.
For these reasons, it does not make sense to require this sort of education in high school.