The reasonable person standard enjoys a certain sort of objectivity, insofar as it protects people from each other.
If that is supposed to show the unique objectivity of utilitarianism, it fails by simply begging the question.
This concerns its fundamental orientation towards objectivity, truth, language, meaning and agency.
The twentieth century was hard on faith in classical objectivity, and in several domains at once.
Written culture encouraged the visual sense, the eye, which promotes distance, differentiation, and ultimately objectivity.
However, they seek to maintain objectivity to the science, and hence other broader-based methods are viewed as being un-scientific.
Some will regard this as noble objectivity while others will no doubt regard it as scientific cowardice.
There were two simultaneous fronts, that of objectivity and that of autonomy (protecting medical science from the pressures exerted by patient associations).