A sense of equality is very important for a variety of good reasons. Whether this is more important than equality is a complicated question that is made more complicated by the fact that equality is hard to measure. True equality is generally rare in a high dimension space. People bring a lot of different things to the table so it is unlikely that two people are doing the exact same - hence differences in pay will always exist. Add to this the fact that people may feel that they are better than average (most people do) and thus entitled to a bump over their peers. Having approximate equality is more realistic. If you accept this, then a comparison against a distribution rather than against a specific individual comparison is a more realistic evaluation.