As noted, Nietzsche was incorrect to identify resentment as the psychological state behind the left; he was unable to identify the true cause, narcissism, because narcissism—shorn from its psychological trappings—is another word for vanity and pride. In other words, narcissism just means the main Christian vice—pride. Since Nietzsche was solidly anti-Christian—the anti-Christ, apparently—he could not admit that the left was actuated by the chief Christian sin; it would ruin his thesis that the left and Christianity are closely allied, slave revolts in morals.
In addition, Nietzsche quite liked the idea that people should become haughty—prideful in a way, as his new aristocrats would be; to be so is, for Nietzsche, almost a lost virtue. While it is difficult to say Nietzsche is on the left or the right, his essence—aside from overt statements about hierarchy—lies to the left; and this is because he wants to destroy tradition, continuity, and also, strangely, because he is a feminine philosopher. He wants you to become haughty and proud, like a woman—he wants you not to be concerned about vanity.
Further, Nietzsche rejects the idea that truth exists; he favours, instead, an endlessly spun illusory web called “truths”—these truths are totally dynamic and changeable; and they serve your self-actualisation. Nietzsche is not an atheist like an 18th-century rationalist or a New Atheist, he is more sophisticated than that—he knows man needs religion; yet his “gods” are not real—just necessary fictions. This idea that we should “spin necessary illusions” is an invitation to behave like a woman—it is women who live within, self-actualise through, an illusory web of “truths”. This is why Nietzsche has always been popular with artists—quite woman-like—with their narcissistic fantasies; and also with the Jews, who, as he remarked, were the first to “get him”. The association with Hitler was libel; Nietzsche would have hated Hitler—only his sister revised him to be Hitleresque. Bottom line: the gods are real.