Uh, yeah. That's kind of it, you want to know what happened that so many fell out before finishing matric - which is an important milestone. It's natural that a certain amount would fall out, but it's bloody high at the moment, which is a problem.
If you have 1000 kids going to school and 60% don't finish matric, you can still look only at the pass rate of the 400 that remained, but it's more important to know why the hell 600 didn't finish.
The assumption here is that all of the 60% actually dropped out and that's a very big assumption.