@Soticoto this is something I found online
"In the 1960s, micro skirts, mini skirts in Japanese, were being very popular among young women. And later, in the 80s, Long skirts dramatically took the position. It was like a backlash and girls changed their mind that long skirts are the coolest. If the anime depicts the 80s, you see a lot of high school girls wearing long skirts. And anywhere in the world, the delinquents tend to exaggerate something, want to twist those fashion trends. So, they liked to wear extremely long ones. It was also a kind of symbol of the rebel. Once they stuck on that mind of "the longer skirt you wear, the more cool you are" they could not stop the LONG SKIRT RACE, even they cleaned up the floor with their skirts when they walk."
Also these types of characters are usually based on sukeban: