Are you kidding? Majority? What kind of society do you live in? Almost all IF NOT ALL the people i know who have got 95+ are perfectly sociable. Just stop.
When you say social, what do you mean? Do you mean that they attend a group tutoring session twice a week, go on facebook for 20 minutes every night and are a part of the school chess team?
The word 'social' means something different to different people. Going back to the original argument about employment, you people are deluded if you think that a high ATAR and HD averages in your uni course is going to land you a job. Employers consider many things like extra curricular activities like part-time jobs, playing competitive sport etc. A lot (not all) really high achievers (99+) generally sacrifice these pursuits (at least partially).
However probably the most important aspect of getting a job is how well you interview.
Its amazing how many people here think that achieving a high ATAR and achieving HD averages means that they are going to be brilliant at a job. There is no job that is anything like school or uni and pretty much every job requires some level of human interaction. Just by the arguments on here I would say a fair amount of you dont understand how the real world works.