I apolologise, but I have not read the whole thread in detail.
However, as someone who has children at state comprehensive while knowing people who send their children to a whole range of different educational settings - state comprehensive, state selective, private, home ed - I find that I am completely tolerant of all those who express their choices in a reasonably detailed, evidence-based 'centred on their child' way:
'We visited all the schools, but felt that Y would be best because of their excellent music provision'
'Working the hours we do, we felt that the hours at Z and the fact that all extra-curricular provision was on site would work best for us'
'P specialises in those with a diagnosis of Q, so we felt that would suit our child well'
Even:
'We visited all the schools and just felt that R was the best match out of all of them.' or 'The small classes / learning 3 languages / focus on rugby / occasional boarding at A would really suit B' are fine.
It is the sweeping generalisations that are more enraging, especially because they tend to have an implicit criticism of those who have made other choices:
'We really want the best for our children, so we chose ...' [ie you don't want the best for your child]
'We really value a good education, so...' [ie you don't value education]
'Private schools are so much better than state ones...' [I have no issue with specific comparisons e.g. X is better than Y for music / rugby / wrap around care / a specific SEN / specific groups of high attaining pupils, but the sweeping generalisation is false]