The group decides POISON is a good thing. So it begins introducing it into the food little by little by little by little. Before you know it everyone is eating poison and not only surviving but thriving.
Anyone can get used to anything at any time for any reason. Insist that the sky is orange and blue is a hoax that doesn't exist and you will have true believers embrace that too. Decree that light is bad evil depraved and dark is good honorable superior and some will avoid the day the light the truth and live in shadows and dark and deceit. There is an audience for everything no matter how bizarre queer peculiar desperate dissolute despicable deranged depraved. Why I don't know. Different strokes.