Goodbye, you have said "have just as much of an interest in education generally as noble does and have been part of it for rather longer than her."
From this, I infer that you are, or were, a teacher - as you say that your interest in and knowledge of education is at least as deep as noble's, who is a teacher. If you genuinely have no interest in and knowledge of education other than as a parent, then the statement I have quoted is untrue.
Empress, teachers have targets for their classes, and yearly appraisals. Where there is a huge gap between target and actual grades, even when the reasons for this might be to do with shoddy implementation over which the teacher has no control, then this may well lead to teachers being, at best 'under greater scrutiny / denied progression', and at worst to capability and removal from post. Anecdotally, there have been some 'interesting' moves / retirements / departures of Y6 teachers based on last year's SATs results, for very similar reasons.