Well the other example that came to mind is a criminal one so I opted to skip it. One of the most successful criminal organizations was willing to work with everyone instead of sticking to the historical "The Irish criminals stick together and don't work with anyone else, the Jewish criminals stick together and don't work with anyone else, the Italian criminals stick together...etc"

If you optimize for hiring the best rather than the best of X demographic you should see a higher bar being met. And this is where excluding other demographics potentially harm's outcomes but it's also the same reason just setting a quota probably doesn't improve performance.