This phrase is itself a loaded non-thing, as it implies that all of this is taking place in a vacuum that was laboratory-generated by white-coated technicians.
But, instead, it's a grimy, imperfect world in which we know that women and other groups have been systematically disenfranchised and continue to be so. So, yeah, maybe someone else whose history does not bear that incredible burden will finally themselves miss out on an opportunity here or there. To those who complain of unfairness, I say "welcome to the world experienced for generations by the very people you now resent because you have to walk in their shoes for a few steps".
>the only mandate for the interview process would be to hire the best person, no exceptions
"Best" by whose standard? People aren't binary or discrete. They exist on a continuum with different strengths and weaknesses. Divergent skillsets, experiences, and perspectives matter, as well as cultivating a culture that at least somewhat reflects your customer base and the wider society in which your business operates. There is actual value to diversity that goes beyond daily LOC output.
Yeah, that may sound cliche, but it is a.) true and b.) vastly underappreciated by many who frequently express their lack of appreciation with statements about "hiring the best person for the job" and the like.