Smoke, it was not meant to be demeaning. I don't know how best to put it. At DHs school reunion it was noticeable how very few had moved far from the area, and he was the only one who had ended up in a professional job in London. My cousin reported similar when teaching in a pleasant city. Bright kids could have got further but wanted to stay close to home. It is seems a factor on the south coast, with bright kids talking about Southampton or Bath, but not Oxford or Imperial.
Aspirations in private school London are very different. Much higher and very international. Schools don't have to push students towards applying for Oxbridge, but rather students considering which is better, Oxford or Harvard. The norm is to work very hard in order to achieve the grades needed.
I can support that medical schools might show flexibility on grades to a student who has achieved exceptionally well compared with the norm for their school and who are likely to be able to cope with the demands of medical school. And who can also show, though volunteering or working, that they know what they are letting themselves in for and can hack the less glamorous aspects of work as a doctor.
However I don't understand an argument that has poorer students considered incapable of finding volunteering opportunities. And regret that poor advice at school may have some students choose the wrong options or not understand how hard they will need to work to achieve the best grades possible.
For some on MN private schools are the root of all evil. Not true in this case, and making that argument wont do much to help students who need to understand that an awful lot is required of them if they want to achieve their ambitions.
I also don't understand why you say steady jobs are only available to the top 10-15% of people. I can accept that aspiring to be a medic is limited to the more academic (not "top") but plumber, supermarket manager, chef? This is probably more a north/south divide, and a whole other debate about whether people in areas of high unemployment should "get on their bikes". (Ducks!)