There are so many generalisations....
Going out instead of studying doesn't automatically mean you have good social skills.
Playing sport doesn't automatically mean you have good social skills.
Being bright doesn't automatically translate to great marks and vice versa.
Bad marks don't automatically mean you're more sociable/not bright.
And so on....
The only thing that is certain is the bell curve....people who are extremely naturally bright and so most likely excel whilst also having innate charisma and the capacity for good social skills etc are relatively rare. Those people are the ones who generally get first pick for jobs.
Therefore the majority (but obviously not all) people who get 95+ because they're bright are going to lack social skills others have. That's the only conclusion we can really make.
Not majority... 95 isn't that difficult to achieve I don't think. My principle keeps giving me an ATAR estimate of mid 90's (not sure I can achieve it with my performance in HSC though), which if true... I'm definitely not one who lacks 'social skills'.
Tbh, I have a mix of both a social life and study life. When I'm at home I dont study all day long, I usually watch TV or watch youtube/talk to people on skype etc for probably half the day and I probably study 1/4 of the time I'm awake (I'm not awake for very long though lol). And when I go out, I love meeting new people, I'd just go up to people and make new friends.
Technically 'genetics' do come into play - you can be socially inactive at times but it may not hinder your ability to socialise with people. If you are 'genetically' sociable, then being locked up in a closet and then coming into contact with people is not an issue. I was talking to this girl who got DUX of my school before (99.95) and she was really friendly and nice, she didn't have issues at all keeping a conversation with me and she's achieving a high distinction average in Sydney uni for a law/international studies degree. However, my friends in the grade above me told me her parents made her stay home most of the time to study... how is she so sociable? genetics.
You can also be absolutely terrible at school, perform academically below average and be really socially awkward as well. I've met many like that in my school.
Also, the guy at my school which I'm assuming will achieve DUX is extremely sociable and goes 'partying' all the time. One of my friends mentioned to me "his got muscles like the size of your head, how can he be so smart?" and I just laugh.