When questioned, advocates of diversity often cite its educational benefits as the reason for promoting it.
Let's subject that claim to scrutiny.
How does diversity benefit education? Its proponents argue that having other perspectives is essential to education.
Right off the bat, there are plenty of subjects where this just doesn't apply. How does more diversity help you to learn mathematics, or engineering, or music?
There are some subjects in which hearing multiple perspectives can be helpful. However, it is easy to exaggerate its importance. Good teaching is most important to learning, not classroom discussion. Good teaching can include presenting multiple perspectives, not just hoping they appear in discussion.
Besides, diversity is a pretty poor measure of ideological diversity. People who have the same superficial characteristics often have very different perspectives.
Furthermore, the same people who advocate diversity tend to be the most opposed to intellectual diversity. They often discourage dissenting views in class, defend campus speech codes, refuse to invite or fund conservative campus speakers, and excuse disruption of such speeches.
There is no empirical evidence to support the notion that diversity is essential or even beneficial to education.
The best schools, however diverse they may be today, got to be the best while they were hardly diverse at all. Indeed, there are constant complaints that the best schools are not diverse enough. Their critical lack of diversity doesn't seem to be stopping them from delivering quality education.
Ironically, the argument for diversity, taken literally, means that minorities are being used for the benefit of the majority. This is because there are more people in the majority than the minority, and minorities are more likely to encounter the majority than vice versa.
Of course, there's nothing wrong with diversity when it occurs naturally. But artificial attempts to impose diversity through racial and other preferences are harmful to all, particularly minorities.