bcos stupidity kekekek
If you think about the times, women were the people used for diving for abalone which to this day, is still one of jejus main exports. On another note, if the females could just leave, and maybe never came back, the men, who mostly did ship stuff (deliver the merchandise and shit) would have to take that job which means they'd have less people for the merchants.
Then during the famine, just imagine the amount of people let alone women, wanting to leave to island would and could leave, men can't leave cuz they would abandon thier fam. I'm sure some did though its stupid but thats how times were. -_-
Was there a rule that no woman can leave jeju island without his majesty's permission?