text: By bilingual education, I am going to assume that you mean teaching children in their native language and the language of a country they have immigrated to.\n\n1) The children aren't pushed to immerse themselves in the new language they need to learn, instead being taught that a mix of their native language and the new language \n2) It is far easier for teachers to lapse back into the children's native language when they get tired of trying to explain a concept in the new language thus defeating the goal of teaching them the new language.