It's not shitty parenting. Kids at a certain age just don't take correction from people who they don't feel have a right to correct them. Sometimes that person is no one. My kid refuses to believe the sun is not a planet. She will argue until she's blue in the face. She has argued that she's a boy. Later that she's a girl. She misgendered people all the time and wasn't open to correction from anyone including me for a while. You think, "call people what they want to be called" is an easy lesson to teach. It is not. It took over a year to make it stick. Kids are just dicks sometimes.