I disagree that schools should teach dialects, but I recognise the intangible value and importance of dialects. The main reason why I disagree that schools should teach dialects is because there are too many variants of each dialect to be unified into one teachable dialect. Civilisation is culturally diverse. For example in Southeast Asia, even neighbours speak different variants of the same Chinese dialect. This situation makes it hard for schools to unify dialects, regulate them, and teach them as one single language. Furthermore, if schools really unify all the variants of a dialect and teach the unified version, there will obviously be a loss of this cultural diversity over generations.
Therefore, in order to maintain the linguistic and cultural diversity of a region with many different variants of a dialect, I disagree that schools should teach dialects.
I personally think that teaching schools dialects could be hard on an individual because it is a professional language and it is like a college level. I personally think that teaching dialects could be hard on a student because they are young and that would be a lot on that individual.
Schools should not teach different dialects of a language because it is unnecessary. Students only need to master the standard variety of a language. The purpose of public education is to prepare children for a career. Learning unnecessary dialects is not necessary for this. It would take time away from more useful subjects.