Like, it's not quite as astonishing as a "government committee on women's health" in which every single member is a man, but it's getting up there.

Diversity is an attribute you want unless you've got some weird demographic quirk as focus for your organisation. Just as you shouldn't try to solve "Two is one and one is none" by just purchasing duplicate tools, but instead look to duplicate functionality, you want senior management (and hires throughout but this pattern matters most at the top) to each have a different range of skill sets and life experiences not just be carbon copies of each other. If the most notable difference between the senior management team is their golf handicaps then they are going to miss all the same opportunities so why are you duplicating their salary cost?

It stands to reason that there are going to be women (in particular) with the innate abilities you want, but with a different set of life experiences that are valuable. If your rivals won't hire them then it's even more likely you can find them available than their male counterparts.

Now, like a "Rust programmers, must have at least 20 years Rust experience" bogus requirement, if you hire based on what people already did, not what you assess they can do in the future then sure, you're going to conclude that there aren't many women, or black people, or whatever in a role that has not historically hired women or black people or whatever. But that means now you're bad at hiring people too.