How schools merely go through the motions instead of actually transfer knowledge from one generation to the next. Yes, there are exceptions, but .... what matters is the general failure. It is allowed because of how the school system describes itself at the state level. It is not responsible for learning. All that the government schools are asked to do is, "offer instructional experiences." There is no requirement for learning; no requirements for learning; no specific expectations upon the students. There is no accountability in the system.
The law says that parents are responsible for their children's education, and that applies whether or not they send them to a school. Therefore, in the eyes of the public schools, if the child does not learn, the schools blame the child or the parents or "society" or TV or something else. Thus, to the schools, failure is always the child's fault, never the school's, even though it is often the case that the schools did not provide proper instruction.
When a business does not achieve its mission, it loses its customers, lays off its employees and goes out of existence. In short, it fails. It must pay off its creditors and dissolve. But when a government agency -- say the school system -- fails to provide the service that it is expected and even claims to provide, what happens? Nothing.
In fact, failure to achieve their mission is the easiest route for public schools to increase their revenues. All they need to do is say, "We are failing because we don't have enough money." It works every time. Never mind that America spends more per pupil than virtually all other countries and in recent decades has among the worst performing schools.
According to international and US Dept of Ed reports, the school system is a monstrous failure, yet not only do none of its schools go out of business, but they are rewarded more and more each year of failure.
We are forced to wonder why this happens, and the answer might just be that the business of the school system is not education, but other things entirely. We are hearing more and more that public school has the purpose of turning out a "workforce." Well, a workforce is best if it is well schooled in basic knowledge, and yet the schools have all but eliminated the teaching of skills and knowledge that former generations were taught -- basic arithmetic facts and phonetic skills for reading. Therefore, the schools are failing in their fundamendal purpose.