Some become chronic litigators. This realization results in fathers dropping out. Boys living with their mother perceive more hostility directed at them by their mother, because the mother is unconsciously reminded of the boy's father. Actively involved fathers participate in their child's homework, sports, school, and extra-curricular activities. This is only achievable by sharing physical custody.
Children really like and prefer a shared physical custody arrangement.
Children are not satisfied with standard visitation schedules. Separations of 10 days or more are much too long. In California, child support is adjusted to account for time spent with each parent. Children need a balance of work and play with each parent for their development. Just spending work time with mothers and playtime with fathers is detrimental to the child's relationship with either parent.