It's not part of dumbing down, because it has always been the case that most sentences refer to "most" and that "most" is the assumed default. Even in academic and medical texts. When you think that not using the correct modifier is dumb or poor communication, then you made yourself guilty of poor communication by stating that all women are born with a vagina, when I could show that some some are born without due to a birth defect. Poor communication skills on your side.