The author doesn't get the first thing about the education system, and complains that the elite schools are too small. That's exactly the point. They are small

The author doesn't get the first thing about the education system, and complains that the elite schools are too small. That's exactly the point. They are small in order to keep them elite. If everyone got into Harvard, many would decline. They'd go to a new, more selective school instead. Because universities are not in the business of education but the business of credentialing. It's about being different, more elite. That's what they sell.