Gratitude is a useful feeling, if you're a part of society and depend on the goodwill of people. It makes spontaneous collaboration possible through principle of reciprocity [0].

I imagine that, when one reaches a certain level of power, the feeling of reciprocity becomes more of a burden, because it gives power to psychological manipulators (e.g. by giving you something that appears valuable, but is in fact worthless, in an attempt to get something valuable in return).

[0] https://en.wikipedia.org/wiki/Reciprocity_(social_and_politi...