Most women have come to think that's normal & acceptable,
Only a tiny handful of women are truly liberated and understand "real" feminine nature,
Ergo, anything that appeals to many, many women must be a patriarchal, oppressive concept.
We'll set aside that the "many, many women" who like slash are actually a very tiny fragment of the populace; most people, including most women, don't know fanfic exists, and when they hear about it, especially slash, they're shocked & horrified that people "waste their time" on such "juvenile" hobbies.
I'm also delighted by the notion that only she, and people who agree with her philosophy, are qualified to decide what's good for all women. I'd probably be angry if I could stop giggling.