Moral Princesses
I liked this term from Bleeding Heart Libertarians. Perhaps it is common but I have not heard it before. It seems apt:
Moral Princesses. In “The Princess and the Pea,” the prince believes that real princesses are so sensitive that a single pea place under 25 feet of bedding will disrupt their sleep. The general idea is that real princesses are sensitive to irritations that wouldn’t bother crude commoners.
Expanding on this idea, some people wish to signal that they are, for lack of a better phrase, moral princesses. They are so sensitive to moral concerns that they are enraged by things the rest of us crude commoners do not even notice. By frequently expressing their sensitivity, they thereby prove they are better than everyone else. (See this paper on moral grandstanding for more.)
Regular person: “Mmm, chicken tikka masala is delicious.”
Activist: “I can’t eat that, as doing so makes me complicit in the British colonialist legacy.”