That's following a given theory.

Other theories exist - such as that people resent being taxed, with reduces their utility more than what they paid, or that people resent being given underserved money, which raises their utility less than what they received.

Also, it one admits diminishing marginal returns on money, what about diminishing marginal returns on utility ?

Maybe there comes a point where, instead of finding Kaldor Hicks optimums of Pareto efficiency, one cares more about fairness, and see this redistribution as unfair. And Kaldor Hicks is about redistribution as can be.