I think you're being a bit disingenuous there, Daisycake. Well, either that or you're a parent who has been misinformed.
No qualified teacher in London (or anywhere for that matter) would work for £14000 - £17000, so we are talking here about nursery teachers. I think (though I am inferring somewhat) that you are talking specifically about Montessori 'teachers'. To be clear: Montessori 'teachers' are nursery nurses. A Montessori qualification is usually equivalent to NVQ Level 3 (depending on the awarding body, of which there are several), but it is not as highly regarded by Ofsted. Now, a salary of £14000 - £17000 is very good for a nursery nurse, particularly when that nursery nurse is only required to work term time only. Most nursery staff working in day care centres earn a fraction of that, and they are required to work year round. Like it or not, that is market reality.
The issue as to whether you or anyone else has the right to comment on what Emma Gower pays her staff (who obviously agreed to work for those salaries in the first place), much less comment on them on an internet message forum, is another matter. Personally, I think you are on very shaky ground, both morally and legally.
As for why the staff turnover rate is 'huge' at The Gower School, I would hazard a guess that staff leave before disciplinary procedures are instigated against them. That's what normally happens in these schools, and I have seen it happen many times. These rotten apples come in, create havoc with other staff members and parents, then leave before they are sacked. And the reason why Emma Gower 'hasn't given parents the chance to voice their concerns with her' is obvious. Well, it is to me, anyway. Would you want to face an angry lynch mob?
My experience is with independent primary schools, by the way, not secondaries. I notice that the teachers have all gone quiet. They know that what I am saying is true.