Isn't it in Harvard's self-interest, and the interest of its students, to have a diverse (racially and in many other ways) student body that prepares students for a diverse world?
A cynic might say that, since Harvard is part of the predominantly-WASP establishment it's in their self-interest to keep their student body predominantly WASPy, with a diverse smattering of minorities. If Harvard turned around one day and based admissions solely on academic merit, they would end up churning out lots of well-educated Asians and Jews, and let's face it, it's not like white people are going to let Asians and Jews run the country so Harvard loses its status as the academy of the nation's leadership.
My understanding of Harvard's point of view is they want a particular mix of strivers and old money. This is not the same thing as racial diversity.
It need not be mutually exclusive with racial diversity.
The point is that they are investing in the growth of their endowment by seeking to maximize future donations from successful alums. With that goal it is straightforward to select exclusively from the two groups most likely to meet it.
I'm sure Harvard has more than one goal to balance in their admissions process.
Harvard's interest lies in keeping itself as the power center of America: produce the future wealthy and powerful, eduate the kids of the current powerful and wealthy. If the current powerful and wealthy has diversity, it is good for them: that is, they would recruit a kid of Chinese billionaire, instead of the kid of City Wok in South park.
Are people who do not attend multicult schools really at a disadvantage in life? Who says Harvard and other elite schools have any interest in "diversity" in "many other ways" than racially? Do their admissions policies include quotas for different religions, political ideologies, professional interests, extracurricular interests, etc.? No, their interest in "diversity" ends at skin color.