The bulk of teachers are so useless, that the education departments decided to drown them in administrative check-box ticking in an effort to ensure they are doing their jobs. This of course doesn't work, as those who have to manage these buffoons, rather monitor and report on well-functioning schools and avoid the poor ones, as them identifying poor performance results in themselves having excessive administrative nightmares and actually shouldering responsibility.
It's basically a game of trying to avoid doing as little as possible, by as many as possible. And the unions keep this going as it keeps their coffers overflowing.
The good teachers try, but eventually realise the futility of the exercise, and then join the game themselves, simply because they have no choice.
Add to this, the fact that teaching is very much a NSFAS-driven choice that those who don't know what they want to do with their lives, happily abuse to get 4 years paid tuition and residence. So basically, the worst of the worst who are able to get NSFAS funding.
Public education in this place has no chance, it is a corrupt system that encourages and promotes the lowest common denominator, punishes excellence and rejects responsibility.