"Dune" was a slightly eccentric movie when it was released and for those, especially reviewers, who hadn't read the book, it just didn't click. The ridiculous long version with all the superficial explanatory sequences wasn't endorsed by David Lynch and was released with the non-de-plume director tacked onto all such releases, Alan Smythe (meaning the studio hired other people to paste together and add stuff to a director's film).
Now a new extended version is available at the end of this month! You can purchase it through our shop from Amazon at a good pre-release discount:
BUY DUNE EXTENDED VERSION AT A2K SHOP
I still appreciate Lynch's vision of the novel and the TV mini-series is a not-so-close second. "Children of Dune" was a better mini-series adaptation. I found the affectations of the "Dune" Sci-Fi Channel mini-series to be sometimes annoying.