If hierarchies exist in nature, why should we frown on hierarchies in human society?
“Nature” alone is not a good source for arguing either for or against human hierarchies. Christians believe that humanity’s fall into sin distorted God’s good creation, so we cannot simply assume that is necessarily translates to ought. Hatred and violence are universal and “natural,” but we believe they are sinful distortions and not part of how God created us. Therefore, simply because hierarchies are prevalent in nature or even human history does not necessarily mean God intended them for his image-bearers.
We should also distinguish between what I call functional hierarchies and social hierarchies. Functional hierarchies are expertise-based to enable an organization’s proper functioning. A coach, for example, has authority over the players on a team, as an employer does over employees. These hierarchies are limited and temporary. A coach has no authority over those same players outside the purview of the team, and coaches can be replaced.
Social hierarchies, however, are often based on a person’s nature. In a patriarchy, for example, men are ranked higher than women; in a racist society, one race is ranked over another. These social hierarchies tend to be permanent and pervasive, crossing different social spheres including family, work, and more. God did create a hierarchy of humans over the rest of creation, according to Genesis (1:27-28). But it is not clear that God created a social hierarchy among his image-bearers. An argument can be made that some social hierarchies (such as parents over children) might be God-ordained, but that relationship changes when both children and parents age.
Determining whether some or all social hierarchies are part of God’s blueprint for humanity or are a result of the fall requires more than simple deduction from nature. It requires a careful study of the whole of Scripture. Given the doctrine of total depravity, there is good reason to be suspicious of social hierarchies in general, as they often become avenues of social oppression. On the other hand, avoiding social hierarchies does not mean we should eliminate social differences or diversity, but merely the inequality between those differences.