It does make you think teachers don't like the idea of being told what to do and even;
'Members of the NUT also want the union to explore the possibility of boycotting Ofsted inspections.'
don't like the idea of being judged on how well they do it.
I don't know the detail but, from the link, it seems that the teaching is of informal as well as formal language and the difference between the two. So it doesn't sound as though the children are expected to spend hours learning about the dative case or the future imperfect tense.
Surely, the basics of grammar, punctuation and spelling are essential. Try re-reading that link but make it about football. How stupid would it be to expect someone to be a member of the football team without knowing any of the rules of the game?