But keep in mind that Harvard's goal isn't to recruit the best students; it's to create an environment where the well-connected can co-mingle with accomplished academics. This is why Harvard and other Ivy League schools admit "legacy" students: it's an explicit recognition that sometimes, who you know does matter. If you have a good mix of smart people, driven people, and politically savvy people from powerful families, they can help push each other to great heights.
I'm not so sure if the model works as well anymore, but also keep in mind that Harvard is almost 400 years old. It worked well for a long time.