What I mean is not that school makes slackers, but school makes people believe that they are slackers, because they never had the chance to experience that they can perform without external pressure. Some people do need pressure to do things, but many people don't. I don't. I mean even if I feel pressure, that's coming from within, and not because my parents/peers would disapprove if I get a C.
But I generally agree with you, school makes people accept that they can't change their life, they need to be slaves/pressured into working ( otherwise they would slack off ).
Also, I would not say that accepting what is forced upon you is discipline. The most disciplined people I know discipline themselves without being force, and that's not something that you can learn in school.