But Star Wars is about... well, wars. It is pretty much a constant state of total war, narrowly focussed on the militaries of both sides - in all of the films. So the question isn't what percentage of the population is female (in that always-shocking 50% statistic that NO ONE would ever guess
,) it's what percentage of the world's militaries are female - generals to soldiers - combatants. For the U.S., that number is 11%. That number roughly holds throughout the Western world - in some non-Western countries it plummets to nearly zero.
Even today, war is overwhelmingly male, top to bottom. The reason for that is moot for the purposes of this discussion - it just is today. So it makes sense that if SW relates to the real world, then it should reflect reality. Because maybe things like Holdo are aspirational, a fantasy of the future, but they don't really reflect the current reality in our world.
Star Wars is also very much about WWII - Lucas constantly referred to the Imperials as Nazis. But the "progress" you mention wasn't uniform - Disney chose to make the Resistance
very diverse (the rebellion, at least in SW and ESB, was obviously pretty much 100% white and noticed then by more than just Sagan) but they chose to make First Order very much like the Empire before it - 95%+ white and male. That imbalance in approach does raise some political flags about "who the bad guys are."
There was that recent case of the critic who called out "Dunkirk" for its lack of diversity and was mocked for it - this is the context of this discussion. WWII was indeed overwhelmingly fought by white people - on both sides - but it's significant that they decided to make the First Order overwhlemingly white and male, and the only black person ever seen in the First Order instantly becomes a good guy before he even fires his gun (and in the same moment we realize he's black,) and the only somewhat significant female First Order character never actually shows her face.
NOTED: first use of 'tard as suffix.