The (Open)Purse though it's more like £15k I now see..
I suspect the elysium fields which you describe, happy is why Calne parents are 'voting'.
For the record, I only know a bit about The Purse (
) but the parents I know there, tbh, shove their DC 'in' at one end and retrieve them, 5-7 years later, job done. My bestie has no idea (or so she says- I hope not disingenuously!) what curriculum her DS is doing, IGCSE (yes) or not (no); she maintains homework etc isn't her problem as she pays others to 'deal' with it! And tells me many other parents feel the same way: 'I'm paying a lot of money so I don't have to worry about it'. Which is why it's possible that parents at Calne thought the school had it all in hand. Not all private parents, despite what you read on MN, immerse and surround themselves with their DC's private education; every nuance, the minutiae, the qualifications and CV of every teacher, the subtleties of every curriculum! Many feel they're paying their money, they're taking their choice.
For the record, my bestie never fails to tell me how many of her DS's teachers are 'Oxbridge', inference: therefore brilliant (and better than your nasty state school). They'd be slaughtered in many a state comp, but the reality is, with hand-selected DC, they can cope, can't they?