People talk about "lack of diversity" and there seems to be an implicit assumption that diversity is always a good thing and that something must be done to address the lack of it.
It's actually incredibly hard to take a very diverse group of people and then expect them all to have compatible values, work nicely with each other sing from the same hymn sheet. In the real world, some people are borderline incompatible with each other.
Surprising as it may seem, every project doesn't need (reads from checklist): a man, a woman, a european, an african, an oriental, an indian, an arab, a native american, a rich man, a beggar, a scientist, an artist, an imam, a protestant, a catholic, a nazi, a rabbi, a university professor, a high-school dropout, a war veteran, a hooker, a convicted killer and a bunch of people with rainbow coloured hair. Perhaps if you need a focus group for a product that needs to have appeal to a wide range of people then it's worthwhile, but that is an exception. Most of the time all you actually need is a bunch of people with the right skills who can work well together.
People from different backgrounds see things in different ways, which might help solve a difficult problem, but how often does that actually happen? More likely you find that arguing over lots of contradictory ideas and opinions at every meeting is just frustrating and inefficient. Whereas people with a similar kind of mindset (whatever their background) can often work very well with each other and achieve a lot.
Perhaps we should relabel "diversity" as "lack of homogeneity" and then just hire whoever is best for the job?