Consider the following two scenarios about a former couple who shares child custody. In the first scenario, the child's father earns vastly more money than the mother. As such, he pays thousands of dollars in child support each month. He then petitions the court for a reduction in child support, alleging that the child's mother is basically refusing to find work.
Now, consider the exact same scenario with the parents' genders reversed. If the child's mother is the "breadwinner" and the father is the parent who allegedly refuses to get a job, does this change how you view the situation? For many people, it absolutely does.