The "slave revolt" in morals

In Beyond Good and Evil and On the Genealogy of Morality, Nietzsche's genealogical account of the development of modern moral systems occupies central place. For Nietzsche, a fundamental shift took place during human history from thinking in terms of "good" and "bad" toward "good" and "evil".
The initial form of morality was set by a warrior aristocracy and other ruling castes of ancient civilizations. Aristocratic values of "good" and "bad" coincided with and reflected their relationship to lower castes such as slaves. Nietzsche presents this "master morality" as the original system of morality—perhaps best associated with Homeric Greece. To be "good" was to be happy and to have the things related to happiness: wealth, strength, health, power, etc. To be "bad" was to be like the slaves over which the aristocracy ruled, poor, weak, sick, pathetic—an object of pity or disgust rather than hatred.
"Slave morality" comes about as a reaction to master-morality. Here, value emerges from the contrast between good and evil: good being associated with other-worldliness, charity, piety, restraint, meekness, and submission; and evil seen as worldly, cruel, selfish, wealthy, and aggressive. Nietzsche sees slave morality as pessimistic and fearful, values for them serving only to ease the existence for those who suffer from the very same thing. He associates slave-morality with the Jewish and Christian traditions, in a way that slave-morality is born out of the ressentiment of slaves. Nietzsche argued that the idea of equality allowed slaves to overcome their own condition without hating themselves. And by denying the inherent inequality of people (such as success, strength, beauty or intelligence), slaves acquired a method of escape, namely by generating new values on the basis of rejecting something that was seen as a perceived source of frustration. It was used to overcome the slave's own sense of inferiority before the (better-off) masters. It does so by making out slave weakness to be a matter of choice, by, e.g., relabeling it as "meekness." The "good man" of master morality is precisely the "evil man" of slave morality, while the "bad man" is recast as the "good man."
Nietzsche sees the slave-morality as a source of the nihilism that has overtaken Europe. Modern Europe and Christianity exist in a hypocritical state due to a tension between master and slave morality, both values contradictorily determining, to varying degrees, the values of most Europeans (who are motley). Nietzsche calls for exceptional people to no longer be ashamed of their uniqueness in the face of a supposed morality-for-all, which he deems to be harmful to the flourishing of exceptional people. He cautions, however, that morality, per se, is not bad; it is good for the masses, and should be left to them. Exceptional people, on the other hand, should follow their own "inner law." A favorite motto of Nietzsche, taken from Pindar, reads: "Become what you are."
A long standing assumption about Nietzsche is that he preferred master over slave morality. However, the Nietzsche scholar Walter Kaufmann rejected this interpretation, writing that Nietzsche's analyses of these two types of morality were only used in a descriptive and historic sense, they were not meant for any kind of acceptance or glorifications.