From the time we are little girls we are taught not to say "no" whether we are explicitly told or it is implied. We are taught to be pleasant, always pleasing and "lady like". Somewhere along the way saying "no" became part of the things that are not feminine. Why? Because saying "no" is assertive and being assertive is not befitting of a "lady".
As a child I was taught that I was never allowed to say no to my mother. Since I wasn't allowed the use of the word "no" I developed other ways to convey my lack of wanting to do things or I simply did whatever task I didn't want to do. I have been told before, specifically by men I have dated in the past, that I don't say "no", I just give a list of reasons why I can't/won't do something. Since I am now aware of this I have been trying to be mindful and just say "no" without giving any explanations to people. Now was my Mom aware that she was playing into a patriarchal and misogynistic plot? No. She was just enforcing a rule that her Mother and Nana had placed upon her. She did this in hopes of raising a "lady", however, my Mother and Father also tried to teach me to think for myself and she instead raised a feminist which obviously worked out for me in the end.
Perhaps this is one of the reasons that women tend to speak more and have a more robust vocabulary than their male counterparts. We are so busy trying not to say "no" that we have to speak more in order to find other ways to say "no" because God forbid we not be pleasing at all times.
With little girls never being encouraged to say "no" and thusly being taught to conform to what someone else's, specifically men's, demands are it any wonder that women and teenage girls have a difficult time being assertive and saying "no" to the sexual advances of men? Stripping little girls of the word "no" sets them up to be compliant both in and out of the bedroom. Parents, listen up. Empower your daughters. Don't strip away their ability to be assertive. If you wouldn't dissuade your sons from saying "no" don't let your daughters lose the power of the word either.