Well firstly not all scholarships are academic - there's music, sport and financial hardship as well.
Secondly, some people are just not academically-minded, and no amount of top-quality teaching will change that.
Thirdly, if you read the posts from private school students above, there are a vast number of advantages to going to a private school beyond academic education. Parents take these scholarships because they want their children to be exposed to that kind of learning environment.
Firstly, I'd just like to add, from now on, this is for the sake of a debate, because I believe that I have many points for public schools in general and I'm not being ignorant.
Well to your 2nd point, I'm really interested in why some people aren't academically minded, maybe someone who knows about psychology can help out here, but I've always thought that those who value the importance and the quality of education will always strive to achieve good marks. I understand that 99.00+ might require "academic minds" but surely there are subjects out there to suit everyone, art-y, music-y, english-y, humanities-y, maths-y, science-y...etc. I think if someone isn't achieving their fully potential, they either aren't giving it their all or have picked subjects which they're not naturally good at and interested in. If you took me and put me in a Studio Arts subject, I assure you, I will get below 30, but I've gotten 40s in other subjects, because those areas are my strengths, whereas Art isn't.
Your third point, I understand that, but I play sports (swimming), music (contemporary guitar). I've volunteered in the community, taken part in charity programs, been involved in tutoring underprivileged kids as well as having (what I consider) a balanced and healthy social life as well. None of that has anything to do with my school and I've had plenty of opportunities to pursue these interests outside of school.
Fourthly, and this is at Paul, again you completely miss the point. No matter how much time my parents spend with me they're not going to be able to conjure up an orchestra to accompany me in concerts at Hamer Hall, or give me the opportunity to play the massive organ there, or make it possible for me to visit China for 5 weeks in year 9. Sure parental attention is important but you're being very single-minded here.
I can honestly say that without parental influence, assistance and attention, I would not have developed in interest in Maths and Sciences. I would also not have become a balanced person, academically. I have, through them, also developed an interest in the Arts, in History, for example. Without parental attention, I would not have been encouraged to take part in Maths competitions from a young age, which has motivated me to perform better in maths. Without the influence of my family, I would not have gone into high school academically confident across a wide range of subjects. Although I have become independent over the past few years, I can't deny that they have instilled the value of education within me. I don't think any school could have done it better than them. They spent time with me, every night, to teach me not only academics, but how to think and how to learn, how to be critical and how to develop interests. Without them buying biographies of famous scientists and mathematicians, I would have never been inspired so strongly. Had my dad decided to work a few more hours every day to send me to a private school, I would have never had the opportunity to develop in the way that I have, no school can shape a child the way their parents can shape them.
They have also successfully trained me to become a moral person, they have discussed societal values with me as well.