What does Diversity mean?

I'm not asking to be facetious, I genuinely don't know what it means in this context.

The elementary, middle and high schools I attended were not only white-majority, but practically white-exclusive. When I graduated, my class had 0 black kids, and 4-5 mixed race latino/a kids, who all did their best to blend in with us whiteys. The environment was not racially diverse, but kids made a point to acknowledge, highlight and value their different ethnic backgrounds. In my mind that's one kind of diversity. How the cultural practices of immigrants eventually changes and morphs as the immigrant family/population adapts to its host country.

In college I was immediately dumped into a melting pot of Indian, Pakistani, Bangladeshi, Yemeni, Jordanian, South Korean and Chinese international students. This group displayed a diversity of ethnicity and there was a certain homogeneity in the opinions this group held. Without exception, every single one of these kids came from wealth. The amount of casual racism and classicism displayed by this group was actually rather shocking. There was a definite lack of diversity in the opinions of that group, but if you looked at them in a picture, or read about their personal histories, you would say it's a very diverse group. That's another kind of diversity.

So when we talk about the value of a 'diverse' workplace, are we judging solely based on melanin content and facial features? Or is diversity of opinion something that is also valuable? How about diversity of background? I would argue that a rich white kid has more in common with a rich black kid than with a poor white kid.

Call Damore a Nazi if it makes you feel good.

I think that there is a reasonable discussion to be had about what we mean when we say 'diversity' in the context of hiring decisions, and I believe that discussion is professional-field specific at the very least, and is possibly more granular than that, down to each and every specific job.