What I don't think many people get is that these types of people and structures and institutions they exist in largely exist in order to perpetuate inequality in many ways.
It's not just google though, this is fairly widespread in America, and I bet many of these companies that practice hiring like that are either doing it because thats what everyone else has done (without realizing the reasons or not articulating the real ones), or because taking those kinds of candidates means not only do you get a potentially useful in their job employee, but you get access to another kind of elite-social capital.