I am late entering the conversation, but I would like to say that while your broad statement is part of the problem, Sadtu in no way are solely to blame. There is a much bigger picture and growing problem which I have noticed.
The teachers at the school (and the school doesn't appear to reflect a strong union leaning) to which my child goes are producing error-filled exam and test papers. It is slowly creeping into their papers, which they set. It has been apparent in English, History and Maths.
So marking becomes a minefield for my child's results as the papers are moderated after the fact. While I am fortunate that one or two marks will not make a significant difference to the outcome of my child's subjects, I can only imagine how it must be hurting others who are on the borderline with their results.
It concerns me for the future. So much emphasis and pressure is placed on the kids to get good results. Their confidence will be quickly eroded if this becomes a norm.
I do not pretend to have the answers. I do feel though that many teachers are under immense pressure to more with less time and resources. And I suppose part of this problem can attributed to some teachers being poorly trained, placed in schools where either they do not want to teach or there is insufficient support from the school & management, or teaching is just a job which puts money on the table.