I'm not sure the exception even holds. The data indicates that most high school dropouts end up going to work which is more than coasting through high school until graduation. It is not like the would-have-been dropouts have hunkered down working hard to become straight-A students. They're just there for the free ride, so to speak, with, as you suggest later on, no real consequences for just being physically present and doing nothing more. Staying in school is now the path of least resistance, lazy choice.