When people affirm the good, but in reality they are, inevitably, less than good themselves, that makes them hypocrites to one extent or another. The conservative idea is that hypocrisy is an inevitable price of civilization. But modern liberals and nihilists constantly attack society for its hypocrisy. They point to people's actual moral failings as proof that the moral standards society upholds are fake. The conservative response is that it's better for people to affirm the good, even if they are flawed in their personal lives, than (as the left demands) not affirm the good at all, in order to avoid being hypocrites.The conservative understanding is that the good is higher than we are. We don't possess it or embody it; we strive, imperfectly, toward it. Thus conservatism understands the co-existence of the objective good and human frailty.
Liberals reject both those ideas. Believing there is nothing higher than man, liberals think that if a person says he believes in the moral good, that means he is saying that he himself is good, or rather that he is identical with the good. (Thus a New York Post reporter many years ago absurdly misquoted Rush Limbaugh's famous slogan, "Talent on loan from God," as, "I am God." The reporter was translating Limbaugh's traditional idea of the relation of man and God into a liberal idea ) In the liberal view, any actual moral failing by a person who says there is a moral good shows him to be a hypocrite, and morality to be a lie. Liberals thus conclude that the traditional idea of the moral good should be dropped, and people should be content with the "merely human," to use a favorite leftist phrase.
Having gotten rid of the traditional, religious-based idea of the moral good, liberals embrace the liberal idea of the moral good, which is compassion, equality, diversity, inclusion, stopping global warming, etc. Unlike believing in the traditional moral good, believing in the liberal moral good does not involve hypocrisy, because for a person to be good in the liberal sense no actual moral behavior, with its inevitable failures, is required: the person merely needs to affirm that he believes in compassion, equality, diversity, inclusion, and stopping global warming. By signing on to liberalism, one is simply and truly good. This is the source of liberals' inordinate self-esteem. Believing in a liberal good that is not higher than the self but identical to the self, liberals feel themselves to be perfectly good, even as they look with contempt and hatred at conservatives who hypocritically affirm, and seek to impose on society, some false higher good that they themselves don't follow.