Because the moral guilt of Progressivism is not concerned with outcome, it can afford to be utterly grand in its aspirations and promises. But one who is concerned with the practical improvement of actual human lives (the true man of compassion) cannot be this way. This second man must focus on what has already shown itself to be useful.
The desire to recreate the world and man requires a state with godlike power. This is the genesis of totalitarianism. Genuine compassion is careful and gradual; it desires to determine the merit and consequences of all thing. It will not exchange a cherished and familiar good for an empty Utopian promise.