Most of the private schools hold back from appointing highly qualified teachers for teaching jobs, if you are more educated then you will have to pay good salary too. Such private schools do not care about the education of the students or the future of the children, they only see business and their own profit and loss. That is why such schools appoint low educated teachers, so that the salary has to be reduced and their profits keep increasing.
Now talking about the children, by telling many school parents that your child is a little week, then he needs extra class, by saying this such private schools hide the incompetence of their school teacher. And parents feel that their child is a week in studies, then they agree to the extra class. And then such schools again demand a hefty fee in the name of extra class and increase their income by asking their own unqualified teachers to give extra classes and those teachers too.
Even after paying double the fees to the school, the child passes in the exam, but like other good school children, he does not know how to become intelligent and then he starts comparing himself with those intelligent children and starts feeling that he is not good at studying. He is weak and he does not understand studies. Thinking of this, he starts getting depressed and separates himself from studies.
When the child separates himself from studies, then even after a lot of efforts by the parents, the child stays away from studies and after a time the parents also get tired of explaining to him. Then the life of such students gets copied without education or with less education, or rather, their life goes out like an illiterate person. And their future is not bad, but there is no future at all.
(Only for those private schools where education is business not religion)