Saw DUNE on HBO years ago. A mess.
Saw it on commercial TV several years later and they had a fifteen minute lead in voiceover explaining the plot, then a voiceover during the movie to explain more.
And was exactly that editing that made the movie more enjoyable for those who hadn't read the book.
AND it was exactly the reason that David Lynch demanded his name be removed from the movie. Watch it again, you'll notice the director's name is now Alan Smithee.
But even with all of that...rain at the end of the movie? Water kills sandworms. Thus effectively killing any chance for a sequel based on the next book.