A person who was morally perfect all the time would be exhausting to know

Susan Wolf argued a 'moral saint' — someone whose every action is as good as possible — isn't actually an appealing ideal. Sainthood would crowd out the jokes, hobbies, and stubborn preferences that make someone a good friend, since indulging any of them steals attention from doing the most good. Moral perfection, she concluded, may cost you a well-rounded life rather than complete it.

— Susan Wolf, Moral Saints — The Journal of Philosophy, Vol. 79, No. 8 (1982)