Are you for real largest SV companies can't find a single "diverse" board member or C level but spend 100s of millions evangelizing how they care about diversity and on employee diversity training?
SELECT TOP 1 * FROM Candidates WHERE DIVERSE = 1 ORDER BY Candidate_Value_All_Things_Considered DESC
or
SELECT TOP 1 * FROM Candidates ORDER BY Candidate_Value_All_Things_Considered DESC
There could be valid reasons to employ either strategy, but I suspect most firms are trying to apply the second and your disbelief that the first query returns zero rows is more a mismatch with the firms' hiring strategy than anything else.
I am not suggesting they have to employee 1st or 2nd strategy. But if you do go with the 2nd don't go down the path of by-weekly employee diversity trainings and diversity being the corner stone of your "values" and communication strategy.