Immoral moralists?

There is a quote I came across some time ago that says, “Waste no more time arguing what a good man should be. Be one.” (Marcus Aurelius, Meditations, X, 16, AD 167). It fits well to a lot of people, except, at least to a certain extent, moralist philosophers—but Marcus Aurelius was one of them …—and theologians, but it certainly fits perfectly with politicians who play the moralist, such as,