Why does Shawn call Tara "fish eyes" and "whore" without any kind of pushback from her parents? Why was this violent behavior allowed?

Shawn is calling Tara "fish eyes" and "whore" because Tara started to wear more make up and lipstick and started to hang out with a boy named Charles. As what Shawn describes, "fish eyes" refers to women who are beautiful but they are empty as the tire. The house is dysfunctional. Father is , in his own way, a misogynist and mother is too scared to fight this.