I don't think this is exactly true. Good social skills are very valuable at every stage of life. They may not be the whole main event, but they are important. Brains are important, too, but it's not the whole main event either. It's strange that this is presented as an either-or proposition. The two skillsets are not mutually exclusive at all.
Please read post #83.
I think you are describing the B table students- who are usually very successful at life. You are right- social skills are important.