Why do people always say parents are always right? I don't think it's true?

My mum never wanted me to move out because she wanted me to depend on her for the rest of my life. Putting my life on hold just for her. She's healthy, she's not elderly. So what rights has she got to put my life on hold for her. My best friend's mum has always been jealous of her daughter's looks, what rights has a mother have to be jealous of her own daughter. My neighbour was domestically abused my her dad, what rights has her dad got to beat his own son?