It's not the burden of an airline to disproportionately represent an underrepresented group of people behind the controls of it's aircraft. Hiring the most qualified and safe applicants is, however, the burden of an airline.
Point being, you haven't seen one black female pilot at DAL because there are hardly any black female pilots in existence. So when one pops up, Delta should toss aside a stack of highly qualified applicants just so they can "nab her"? Why? So they can say "hey look how diverse we are!" What does that accomplish? Who is that going to impress? Passengers? Because when passengers get onto an aircraft, in the back of their mind, they don't care what color their pilots are. Black, white, asian, pacific, whatever, they just care that they are competent.
Delta probably doesn't have any black female bicurious three-toed pilots, either. They better find one quick.