Because in a dominance hierarchy like patriarchy, those with more historic and institutional power feel entitled to abuse those with less, who are supposed to take that abuse stoicly and with grace. When they don't, they are seen as out of line - drawing attention away from the top of the hierarchy (where it supposedly belongs) and putting it on themselves.

“It (Kate Manne's book, Down Girl) argues that misogyny should not be understood primarily in terms of the hatred or hostility some men feel toward all or most women. Rather, it’s primarily about controlling, policing, punishing, and exiling the “bad” women who challenge male dominance. And it’s compatible with rewarding “the good ones,” and singling out other women to serve as warnings to those who are out of order. It’s also common for women to serve as scapegoats, be burned as witches, and treated as pariahs.”

"Her humanity may hence be held to be owed to other human beings, and her value contingent on her giving moral goods to them: life, love, pleasure, nurture, sustenance, and comfort, being some such. This helps to explain why she is often understood perfectly well to have a mind of her own, yet punished in brutal and inhumane ways when that mind appears to be oriented to the wrong things, in the wrong ways, to the wrong people — including herself and other women."