While today the micro-miniskirts of the 1960s seems horrifically sexist in the 2000s, the truth was, they were a rebellion against the fashions of the 1950s, exactly the same way the flappers were in rebellion against Victorian corsets. My mother was in her 20s while the original series was airing, and she wore skirts just as short as Uhura's. Hell, the high school girls at the private Cathlic girls school I attended in the 1980s (when we had to kneel on the floor and have our hems brush the carpet or risk being sent home to change clothes) had skirts just as short in the 1960s.
I too wore mini-skirts and even micro-mini-skirts (one year they were in fashion.) However, in those times, pretty much that was what you got if you were under the age of what, 40 or 50? Only older women wore skirts that weren't mini-skirts. In some respects, it was a lack of nice stuff to wear. Dresses/skirts were mandatory in my schools through around 1969 or 1970, if memory recalls, and my dad didn't allow me to wear slacks or jeans to school until around 1972.
You couldn't GET anything but a mini.
Not everyone was in rebellion against the 50s, I was born at the tail of it and didn't recollect their styles, obviously.
Some of us wore the short skirts due to lack of alternatives or due to peer pressure and not to be feminist or liberated or whatever.
Lest y'all think I'm an utter prude, I just didn't like showing off my ass. I wasn't averse to low-cut or tight tops.

So I'm partly a hypocrite. Still, my bra never was allowed to show.