“Didn’t these idiots ever hear of something called an “F” on school assignments?
Don’t these morons know that if a student collects enough “F’ grades, there is this thing we used to call “staying back”?”
They know. Knowing and caring are two different things. Kids like that, angry, fighting their parent, deliberately failing just don’t care. Grades motivate people that believe they have a future.
Or at least have some concept of future. Many many cannot conceive of anything past Saturday evening. For many The Future is a myth used by parents/police/teachers/et al to keep them from having fun. This attitude can and usually does persist through life.