If gender "didn't matter", then why has every president, every vice president, and every Speaker of the House in US history been a white male?
Surely you're not implying that it's all just some bizarre coincidence, one which has nothing to do with race or gender, that these scores of white male leaders were simply the most qualified individuals for the job... that there has never before, in the entire history of the world, been a female or a person of color who has been qualified or possessed the necessary attributes to lead?
Your assertion that this historic appointment "doesn't (or shouldn't) matter" implies just that: that gender is not an issue, and therefore that the reason there has never before now been a female President, Vice President, or Speaker has nothing to do with gender discrimination and that by some bizarre coincidence the most qualified candidates for these positions have invariably and exclusively been white and male.
If that is your position, it is a frankly ludicrous one.