Probably because it creates problems. You need math teachers who speak that language for one. Then you divide the student body, probably along racial lines fo

Probably because it creates problems. You need math teachers who speak that language for one. Then you divide the student body, probably along racial lines for the most part, which isn't a good thing. And then lastly, it will only hinder the language development of the ESL group which will come back to bite them later in life.