Okay, let’s take mens’ skirt-type garments into account – kilts, Middle Eastern robes, etc.
Robes fall well below the knee and are made of flowing, heavy fabric. About as modest as a spacesuit, really. Depending on the length and width of the garment, however, it can become very easy to tangle yourself in your own garment. An ankle-length dress on a nurse would be…well, it wouldn’t be as bad as those little miniskirts, at least, but it’s not as practical as some form of slacks.
Kilts. Usually at least below the knee, and there are some very fine-looking and elegant men’s kilts out there, as well as some very, ah, utilitarian ones. Many women find them devastatingly attractive, really. But even a below-the-knees pleated garment drives me nuts, personally. My skirts are always shin-length or lower; anything that ends near my knees makes me feel like I’ve got nothing on at all, and I show the world my underwear when I bend down. And nurses need to do a lot of bending.
As for traditional nurse’s skirts, they are roughly knee-length, IIRC, and STRAIGHT. I can’t even begin to describe what wearing a straight skirt is like. Imagine if your legs were tied together just above the knees – fairly loosely, but quite securely. It’s fine for a business suit, since you don’t have to run around much in one of those, but for any sort of physical exertion…
It’s the same reason athletes don’t wear skirts. Not because it isn’t “pretty”, because it just isn’t practical. Should a nurse be willing to give up a little more comfort for a little less practicality and a little more attractiveness? I want my nurse concerned about me, not her dress.
As for dressing nicely for work, well, I think I’d rather enjoy dressing '40s style. I wear pressed slacks and a blouse to work most days. Today I’m wearing a black dress with brown velvet leaves on it, very pretty. Yesterday, white blouse, black slacks, black waistcoat. Tomorrow, probably much like yesterday (I only have the one dress nice enough for work while not being formal enough to wear to the the-ah-tah). A lot of women will dress as casually as they can get away with because it’s so much more comfortable. Comfortable workers are more efficient.
That being said, I like to wear the nicest clothes I can afford. You may think what you like about the desire women have for comfort, but having worn the business-standard for both genders I can tell you which I find more comfortable!
Oh – and many women would be insane to not wear some sort of shorts or pants or something under a skirt. Talk about uncomfortable. It’s hard to understand,again, unless you have experienced it firsthand.