Not he that adorns but he that adores makes a divinity. The wise man would rather see men needing him than thanking him. To keep them on the threshold of hope is diplomatic, to trust to their gratitude boorish; hope has a good memory, gratitude a bad one. More is to be got from dependence than from courtesy. He that has satisfied his thirst turns his back on the well, and the orange once sucked falls from the golden platter into the waste-basket. When dependence disappears, good behavior goes with it as well as respect. Let it be one of the chief lessons of experience to keep hope alive without entirely satisfying it, by preserving it to make oneself always needed even by a patron on the throne. But let not silence be carried to excess lest you go wrong, nor let another’s failing grow incurable for the sake of your own advantage.Gracian, The Art of Worldy Wisdom
In a similar line of reasoning, it is better to be feared than loved. The dependent person fears for their own self-interest, and as long as they see in you, a source of alleviation of worry, and a provider of security, then they will remain loyal. The person that thanks you no longer needs you. You become either dispensable to them, or a rival.