"Why is the bright poor kid any more worthy of a decent education that the less academic poor kid?"
Why is the kid from a well to do family allowed to gain a life and societal advantage over a kid from a poor family, even though they are of equal ability and potential, just because his parents can send him private?
I understand the point about the difference between Big Name public schools and just private school, in regards to Old School Tie, networks, internship-for-your-DD-if-you-offer-my-DS-a-traineeship etc; however, come what may, even the least private school still offers selection if only by 'parent willing to pay'. This alone guarantees a modicum of there being a standard beneath which you cannot fall. Disruption doesn't have to be managed, it can be turfed out; ditto SEN; ditto 'colourful personalities'. The state sector cannot do this.
I am also opposed to grammar schools. I went to one, and they were also a bastion of privilege, though the advantage wasn't wealth; it was less classroom disruption, no 'slower' DC to take up the teacher's time, highly educated , motivated teachers, (some of whom would be eaten alive in a badly managed, underfunded, demoralised SM).
I recall an apposite remark: The Left hate Grammar Schools because they entrench privilege; the Right love Grammar Schools because they entrench privilege... the same could be said of private schools!
I cannot see why 'the clever' cannot be taught in the same schools, if not same lessons, as the less academically able.
However, this isn't about selective education, this is about the 'leg up' the wealthy can buy their DC. Funny how that's acceptable, but a 'leg up' given to a clever DC with potential from a bog-standard state school via a lower offer made for uni, isn't...
Final point: I am being misunderstood about the term 'privilege' in the context of how I have used it. I am not talking about big houses, flash cars, skiing holidays, here. I am talking about the privilege conferred by being able to access small classes of like-minded, non SEN, non poor fellow pupils. This goes a fair way towards being able to buy the material things mentioned above. I understand the 'scrimp and save' brigade- but do they understand that for the vast majority of the populace on the average wage, there is no way they'd ever be able to find £13k pa per child to buy this privilege? To even countenance it, you are one of life's 'Haves'.