Is there some underlying assertion here that woman enjoy sex less than dudes? Or that sex is some kind of favor to men on the part of women without mutual enjoyment? Not having sex with someone is pretty easy if that other person is a shitty person. Otherwise I think both genders enjoy genuine intimacy and physical contact by someone they enjoy being around.
It's a reference to an old Greek comedy called Lysistrata from 411 B.C. The gag was, in order to end the Peloponnesian war (460 B.C.), women colluded to refuse sex until the men come to their senses and stop the war.
i think there is very real fear women have to take into account whenever considering getting involved with any man. you don't really know if he is a shitty person until you have invested some time into him, and that has its own costs. the risk of getting impregnated, ditched, and stuck with the bill is just too big. these days.. even more so. i think this is a very natural outcome in the face of the rampant misogyny (in the case of S Korea) or revocation of reproductive rights (USA)
Or maybe you should read the article first before jumping to conclusions.
The idea behind the movement is individual resistance against what it defines as a conservative political environment and the corrosion of reproductive rights.
So the idea originates from a fringe South Korean feminist movement that uses a "sex strike" as a political protest. shrugs