homogeneous teams made up of people who think the same way, have similar backgrounds etc are more likely to have blind spots. Having a diverse set of viewpoints involved in decision making means you are less likely to overlook some corner case that is obvious to some people but not others.
And how do you define "diversity"? Through externally presenting traits? Through who and how people decide to have sex? Much of diversity efforts seem to focus on these things instead of actual diversity of thought and experience.
You might have three "white guys" and one grew up in poverty in the US south and made his way out of it, one who was born in a tiny town in eastern europe, and one who grew up in a middle class family in the SF bay area. But there are many people, if seeing those three guys in a photo, would make some snarky comment about "tech bros" or "white dudes" and completely discount the fact that they are three unique people that have grown up with completely different backgrounds and come with completely different experiences and approaches to life.
Most, if not all, diversity efforts I have come across, including where I currently work, focus exclusively on externally presenting traits like race and gender, with the explicit goals of reducing the numbers of white men in category.
