Sorry, I realise I am guilty of over generalising privately educated people. I think your point 2 contradicts point 1 but you are, of course, correct that you have to have the academic excellence to get in. No amount of teaching DJ'ing to gangstas at youth clubs in Tottenham is going to get you into Natural Sciences at Cambridge if you can't do the maths. The critical point here is the application and interview. Given two candidates with similar results they will pick the 'trumpet playing circus performer' over the 'quiet grey blazer wearer' because they are more likely to have a rounded personality which will allow them to thrive amongst all the other things that university life entails. A real world example of this: Two guys in my A-level physics class at school were given offers to study natural sciences at Cambridge. One who was quite shy and introverted without much social life but very hard working with a natural genius for maths and physics. He had a difficult interview and was made a very tough offer conditional on getting the highest possible grade in all his A-levels and two STEP papers. The other guy was more outgoing and I don't remember what his requirements were but they were more lenient. I remember us all discussing the injustice of it in school and the admissions coach said that in his experience they did this as a test to see if he was brilliant enough that they would take him despite the risk that he wouldn't integrate well. They both got in by the way.
I have to say though, I think the current lack of poorer kids from more ethnically diverse backgrounds is more a reflection on the terrible quality of the state education system in inner cities than it is on the universities themselves. When I was thinking about which A-levels I wanted to do (~20 years ago) it wasn't possible at any school in my borough to study the required combination of A-level subjects for a science or engineering degree at say Cambridge, Imperial or equivalent. I switched to the private system for the last 2 years of school because of this and my fellow pupils were light years ahead of me, it was a real struggle to catch up. Their GCSE maths exam (taken at age 15) was set by a different exam board than the state school I left. The first question in their exam was "Factorise the quadratic", the first question in mine had been "Whats the time?" followed by a picture of a digital clock at a railway station. I could hardly answer any of the questions in their GCSE maths exam, I'm sure they would have been able to answer all the questions in mine.
I have to say though, I think the current lack of poorer kids from more ethnically diverse backgrounds is more a reflection on the terrible quality of the state education system in inner cities than it is on the universities themselves. When I was thinking about which A-levels I wanted to do (~20 years ago) it wasn't possible at any school in my borough to study the required combination of A-level subjects for a science or engineering degree at say Cambridge, Imperial or equivalent. I switched to the private system for the last 2 years of school because of this and my fellow pupils were light years ahead of me, it was a real struggle to catch up. Their GCSE maths exam (taken at age 15) was set by a different exam board than the state school I left. The first question in their exam was "Factorise the quadratic", the first question in mine had been "Whats the time?" followed by a picture of a digital clock at a railway station. I could hardly answer any of the questions in their GCSE maths exam, I'm sure they would have been able to answer all the questions in mine.