@SouthLondonMommy
I think with your arguments its hard to put forward a counter argument without appearing cold hearted as there is an obvious moral appeal to what you say.
However.....the word 'fair' thought only four letters could take a few philosophical or political tomes to discuss in entirety.
One persons idea of fair is different to another's sometimes linked to their political persuasion.
We have multitudes of areas of inequality that many would say were unfair (e.g. wealth distribution) and we can watch Keir Starmer make this clear to Boris Johnson every week . .not everyone sides with Keir.
I think the point is increased diversification and inclusivity can not be stated as a goal which is universally accepted and a natural desire of all people. There is as I said before a political undertone to these views
We can get to some challenging arguments if we extend the argument that different sectors in society should have a proportionate representation at oxbridge or any other leading institution.
There is the morally attractive argument that private school children should take up places in proportion to the number of high A level grades awarded but should then we consider proportionate representation of other societal divisions.
e.g. if x% are of a certain ethnicity x% of oxbridge should be from that ethnicity. Definitely.
50% of the population are women 50% of oxbridge should be women. Definitely.
We could could go on with this analogy but you reach a point where the argument is that the Oxbridge community should truly reflect all society and is this achievable?
For instance Oxbridge is by definition academically discriminatory but as there is a correlation between wealth and academic achievement there will be a de facto discrimination against poverty but certainly not by design.
I was reading the VC of Cambridge welcimg the increase in state pupils and congratulating the work of its outreach group. If you inverted the statement and it became 'we welcome the reduction in proportion of private school students....' it suddenly becomes offensive.
The fairness argument you present follows the idea of 'equality of outcome' in political arguments (where there are goals and quotas for differing sectors) rather than 'equality of opportunity' (where everyone has the same initial opportunity but outcome isn't guarenteed).
It would be a good oxbridge politics interview question actually. Should there be limits on private school entrants to elite universities ?? Again I am slightly cautious about statements of increasing diversity being taken unequivocally