Once upon a time, not turning up for an awards ceremony held a kind of clout: “When a writer doesn’t show his face,” as DeLillo wrote in his 1991 novel, “Mao II,” about a reclusive novelist who becomes a prisoner of a terrorist organization, “he becomes a local symptom of God’s famous reluctance to appear.” Now it feels a little rude, like not showing up to a dinner party held in your honor.