Not sure why they draw the conclusion that the aversion is about not wanting to upset the social hierarchy. That's an amorphous statement in any case and carries different connotations.

Seems a more succinct conclusion is that it's about fairness. Most view the economy as a zero-sum game, and we generally measure our standing in society relative to others. So, the idea of redistributing wealth to the point where relative fortunes are being inverted may violate our sense of fairness.