Tell me of your homeworld, Usul

I've just finished rereading Dune, having first got through it in my teens. In my head, the book is rather overshadowed by the 1984 film - which I adore - and more importantly by the stickerbook that I and my classmates devotedly filled up because of/despite being far too young to see the film.

As before, I was struck by the richness of the story, the wealth of memorable characters, the complexity of the court politics and the worlds created. The desert planet Arakis is an extraordinary creation, with sounds, smells and language, and a whole ecology, that feel tantalisingly real.

It's not perfect. A lot of the dialogue is horribly clunky, and I can see where the film has cut down or modified examples to make it work more smoothly. Early on, Herbert constantly tells us what's about to happen, which initially adds to the suspense and then just gets annoying. It's at its best when we're left with more work to do as readers, spotting the gaps between what people think they're doing and what they're seen to be doing, or being able to join up the dots of future history. Quotations by Princess Irulan discuss events we're yet to see, placing them in a context of an as-yet-unknown future and adding a scale and importance to the most minor scenes of intrigue. It's a thrill when we meet her in person towards the end of the book, as if we've entered some new age.

Nosing through the web, I've found analysis of the book's links to drug, ecological and countercultures, the islamic influences and so on. I've also found plenty of criticism, such as Samuel R Delany taking

"offense that the book's only portrayal of a homosexual character, the vile pervert Baron Harkonnen, is negative."

Wikipedia, Dune (novel)

At least as objectionable is the simplistic gender binary that runs through the book, with hero Paul fulfilling a prophecy to be the only man capable of doing something normally the province of women. When he succeeds and fulfils the prophecy, it seems to prove the truth of this strict binary division between men and women.

"Paul said: 'There is in each of us an ancient force that takes and an ancient force that gives. A man finds difficulty facing that place within himself where the taking force dwells, but it's almost impossible for him to see into the giving force without changing into something other than man. For a woman the situation is reversed ... The greatest peril to the Giver is the force that takes. The greatest peril to the Taker is the force that gives. It's as easy to be overwhelmed by giving as by taking.'"

Frank Herbert, Dune, p. 505.

That certainty sits oddly at the end of a book so otherwise - brilliantly - caught up in doubt, counterplot and pragmatism, where characters die brutal deaths suddenly and without warning.

I found myself wondering how rare it is in sci-fi for a prophecy not to come true, or a young hero turn out to be not the messiah... Yes, I'd welcome examples.