Changing social conventions has a cost. When we extend social justice beyond respect for difference that people have no choice over, such as race or sex, to roles that they choose, such as religion or gender, the justification for allowing everyone to defy any particular social convention must be a rational cost-benefit assessment. Many people enjoy the ritual interactions specified by social roles; they are part of their identities and one of their terminal values.

Not to mention that many social conventions serve a purpose beyond people enjoying them.