Discipline, respect for authority and other people, and good moral character start in the home. It is not the school's job to teach those things, but they should demand its presence in those that attend and remove those who fail to demonstrate it with extreme prejudice.
It takes both, but home and school need to be on the same page re setting limits, maintaining order and accountability.
It is a rotten culture that can not be fixed. They should have never been taken from Africa and should go back to avoid the evyils of the white man. We are not compatible. A few exceptions do not disprove the rule.