the reason is that anytime a woman could do something that women werent supposed to be able to do.. they were branded as a witch and executed... cus back then they didnt see women as people... just as objects.. and if their women could do stuff that women werent supposed to do... then they were called witches and executed...
this is why witches are associated with women... it was an excuse to execute women who didnt fit their description of what a woman should be.