It is one who has slaughtered (a beast), who says the liver is not suitable to have as relish.
Traditionally, livestock has been reared for meat among other things. The liver is edible, and a rich nutrient source. It could however stand at the bottom of the list of relish choices, for one who has plenty of meat at their disposal.
One pays little or no regard to certain things when they have other more valuable things at their disposal.