I have read all this thread with interest.
To me it boils down to this.
Either we believe that the top 1-10% of society are there essentially because they deserve it, because they have 'good genes' and 'have inherited their parents' intelligence'; conversely, in this model (the Tory model, really) we believe that the 'poor' or 'lower classes' are also there because they 'deserve it' (ie worse genes / less 'naturally clever). In which case, if we follow this model, we push to have segregated schools for the 'bright / wealthy' kids (ie grammar schools) & 'technical schools' for those who are 'not bright / not wealthy' ie keeping them in the place within society & teaching them 'practical' things that they will need in their jobs as builders etc. This is the essence of it really: that these two groups (bright/wealthy versus not bright / poor) have essentially different characteristics that should be catered for separately, with no hope or wish in fact to work towards social mobility. In such a model, if there is an exceptional 'bright / poor' kid, they will manage against all the odds to get to a grammar school (no mention in this model of the countless poor / medium kids who will never manage).
Or alternatively we believe in a model which says that wealthy people are wealthy largely because of their parents' privilege, because of luck, because of hard work yes but luck and inheritance as central. In that case, if we oppose the horrid inequality in our society, if we believe that all kids deserve a chance in a good educational system that is truly for all, then we properly fund our schools, segregate kids as little as possible, mix all social classes as that is the best model worldwide to help the majority and to help social mobility.
I find the idea that wealthy people are naturally more intelligent so far from my everyday experience and also so far from my political / social beliefs that I naturally am opposed to the first model and support truly good and well funded comprehensive schools within which children of all abilities & talents can thrive. Yes to the expense perhaps of maintaining the horrid inequalities of the current system (ie the most wealthy / most bright may not maintain THAT much of their privilege) but to me that is a price well worth paying.