Honestly, the more I read about all those "diversity initiatives", "outreach campaigns" and "pushes to increase H1B" caps - the more I wonder about the intent and motivation of the people pulling the strings and funding the groups fighting so hard to further those causes. My comment is only tangentially related to hiring practices. Maybe age has turned me into a cynic, you can never know for sure, but this seriously…
I think what they mean by "not diverse enough" is in comparison to the pool of candidates. Under the hypothesis that race/gender/ethnicity/sexual orientation/nationality/age are uncorrelated to performance/ability of the candidates, it implies bias in the selection process. Which isn't only an ethical concern, but also a business one: it means they're not hiring the overall best candidates. Of course, there's also so…
We are infinitely certain of this, which explains many things.