But if all he said was that God is dead (whatever that meant) that morality is a crock; and that everything is a matter of perspective (except, of course, for Nietzsche's own perspective which is true) what else is there to learn from him, except how to rant?
I do not think that N ever qualified his own "perspective" as "the true
N is not in the truth business, N is about what future men can shape.
Many centuries of seeming
truth seeking has lead - and it's still leading - mankind on the brink of extinction.
Maybe we don't see it yet, and I guess that it is harder to see it coming observing from America, but it is a widespread feeling. At least, I guess you would not object that there are people having that feeling. (Kaczinski shared that feeling too, although I guess he did not know anything about N, at least when he wrote the manifesto).
If you believe that what has been used so far by the Christian West as reasons for living can no longer be used - and ultimately this is what the death of God is about - then N must have some appeal...
In this "perspective", why your main concern is learning? If he ever said something like "I hold the truth", then... it'd be understandable. But this is not in N - OK, maybe you would argue that Zarathustra... But in order to keep this post short let's leave the teachings of Zarathustra out of this.
N's philosophy is a continued, and IMO successful, attempt to show (and I don't mean "prove") how much what you hold as dear and sacred it is not what it seems. And "truth" is possibly the main victim.
It is also a continued, and IMO successful, attempt to show how much of what you condemn and reject is part of what makes you alive and thinking, seeking for truth.
And if you undergo this process, reviewing and rediscussing all those beliefs and truths - that maybe you do not even realize that you have - inherited and adopted, which have guided you so far in living, maybe you end up not adding some truth to your database, but with some wholly new approach to life and action.
Having said this, I do not imply that N is a kind of moral preacher.
The philosophy of N is his will to power. Not only that, N philosophy is
will to power. I do not mean that the "will to power" is one of the elements of the system N (the man would have been horrified if somebody ever maintained that he had a system - which a number of scholars did, anyway). I mean that the will to power is the "real thing" and the subjects - Herr Nietzsche in this instance - only accidents. I can rephrase that saying that his philosophy it's not his perspective, it's the perspective that is him, N is the embodiement of this "perspective" - a perspective that has become what it is.
And that "perspective" must have occurred, occurred with no aim. (And will occurr again and again, for ever and ever, because the aimless eternal recurrence of the same things is the whole history of the world).
So, in this "perspective", your question "what to learn" is devoid of sense. (And probably you are going to think that what I wrote is perfectly alike :-).
And... yes, IMO he's an unsurpassed model as far as ranting is concerned. Indeed he perfected the art. I would not enjoy his work so much with no ranting - actually I see taste, style, art where you see "ranting".
Btw, there must be some deep link between Philosophy and ranting - a good deal of Plato is about ranting too, after all.