One has to be balanced (duh) ...
A socially well-adept person with some intelligence can schmooze his or her way through the system for quite a while, but ultimately they will just end up over their head, and when you're up there, people are smart enough to see and hear BS.
On the other hand, a 12-year old college grad may be smarter than three of me combined, but lack of socialization will be totally detrimental to your ability to work in society ... because very few professions involve absolutely no interaction with other people.
The ability to read nonverbal cues, the art of speaking and writing to people, etc. are invaluable for "advancement" in the sense of moving up the ranks of wherever you are (which for <em>most </em>people is their goal).
Speaking of "good" schools versus "crummy" schools, I was a product of the "good grades = good school = good job" theory of parenting. I got to the "good job" part of things but not without bumps in the road. However, along the way, I met and became friends with plenty of smart, talented, and compassionate people who did not go to "Excellent undergrad school ranked in the top 20," who did not go to "Excellent professional school ranked in the top 20," and were far better people than I.
Good grades and good schooling <em>may</em> result in landing a good job, but is not a guarantee.
Nor are "not good" grades and "not good" schooling automatically result in a "bad" job.
Sure, I moved to Irvine so my kids could go to one of those "top" schools. I am not no naive as to think that just by going to IUSD that guarantees "good school = good job" and in fact, acknowledge that the main factor in a child's academic success is parental presence. I do think that by placing my kids in this environment, at least the resources are there at the school system for them to take advantage of, and enrich themselves. And a little bit of competition serves to sharpen you ... so long as it is done with integrity.
Speaking of integrity, I want my kids to learn that values - integrity, justice, and compassion to name a few - are just as important lessons to learn as American history or chemistry.