It actually did seem like a stretch to me that Hollywood types would be familiar with Dune - Lucas never really struck me as a hard core science fiction nerd - so yeah, this would explain the jump from the hard core science fiction literature world to the movie world. I mean, I suppose that's always true, scriptwriters are the link/filter/lens between literature and two hour movies but it took an easily assimilable picture book for others to get it.

That would explain something that's been bugging me. Dune was too hard to do as a movie so Star Wars filled the space.