I find the linked HBR article• quite interesting since it proposes a mechanism for diversity improving performance: in non-diverse environments, out-group members receive less support for their ideas. Assuming performance is equivalent and that the ideas are just as good, it means you're throwing away some percentage of your employees' ideas without justification. That's just hamstringing yourself.

Another one mentioned there is the bit about success among certain groups correlating with whether you have a member from that group. There are others like that but I hadn't heard about the first thing before.

• https://hbr.org/2013/12/how-diversity-can-drive-innovation