But I think of it as being a little like finding a quarter (10p piece, for you Brits

And one of the things that makes it possible for me to freely enjoy seeing women in skirts is that (at least as far as I know) they're mostly wearing skirts because they want to.
When I was growing up, girls and women wore skirts because they had to, or because they would get funny looks and nasty comments if they didn't. If a girl wore trousers to school (any school) back then, she would get sent to the principal's office, where they'd call her mother to bring her home to change into "proper" clothes. If a woman wore trousers to my church, even a fancy "pants suit," you could be sure that she would hear about it from everyone. As for work attire, in few kinds of jobs that women weren't excluded from, they were expected to dress "properly", which meant a skirt (and the right kind of skirt) if they didn't want to get fired. Not only were women required to wear skirts, they were expected to go to great lengths to "be attractive" -- make-up, hair styling, stockings, high heels, etc. And if someone took it as a license to grope, well, that was the woman's fault for being "too attractive." Apropos of this, does anyone remember what life was like for airline stewardesses back then? ("Coffee, tea, or me?")
You can see how few women were wearing skirts because they wanted to by the speed with which most of them switched to trousers once they had the choice.
So when someone talks about the "good old days" when women wore skirts all the time, all I can think of is how much more restricted women's lives were then and how much their lives were dominated by the need to be attractive to and acceptable to men -- because it was men who controlled their lives. I react to such talk the same way I react to people who talk about how charming the Ante-Bellum South was back in the days when the Darkies sang their happy songs in the cotton fields.
I say: no, thank you.
I prefer the way things are now, even if it means I don't get to see as many women in skirts.