The ancient Greek understanding for ethical was the usual, the normal. Ethics encompasses a code of conduct and may be moral or physical with application according to past practice or a projection of the desires of a promoter.
Aside from the etymology, the word ethic has a strength simply because it sounds good. A proposal under the banner of an ethic is presented as positive. A denial automatically is defensive, and the more general, the more platitudinous the expression of the ethic, the more difficult the task of the objector.