Parenting has changed in the last decade. It used to be stronger and more accepting. However you see, some kids get loved differently by parents. Some parents seem to love one child over the other because of different reasons like having a favorite child. But kids need unconditional love. 

Kids who get unconditional love grow up happier than children who is only loved for what they accomplished. They have greater stress resilience. Let's not forget healthier brain development.  They forge a healthy relationship in their adult years. That's why all children need to be unconditionally loved. They will have brighter futures.