I believe that utilitarianism refuses to fade from the scene in large part because, as the most familiar consequentialist theory, it is the major recognized normative theory incorporating the deeply plausible-sounding feature that one may always do what would lead to the best available outcome overall.
Samuel Scheffler, The Rejection of Consequentialism: A Philosophical Investigation of the Considerations Underlying Rival Moral Conceptions, rev. ed., Oxford, 1994, p. 4
[C]ommon-sense deontological morality, standing between egoism and consequentialism, sometimes seems to be caught in a kind of normative squeeze, with its rationality challenged in parallel ways by (as it were) the maximizers of the right and of the left: those who think that one ought always to pursue one’s good, and those who are convinced that one should promote the good of all.
Samuel Scheffler, ‘Agent-Centred Restrictions, Rationality, and the Virtues’, Mind, vol. 94, no. 375 (July, 1985), p. 415