Have you read the book?

Frank Herbert used Lawrence of Arabia as one of his inspirations. So, sure, there is some of the white savior thing going on, but it's based on an actual historical figure.

As far as the sexism - again, the novel follows historical norms. Any faithful retelling of, say, the life of Henry VIII or Suleiman the Great or the Japanese Shoguns would also be perceived as incredibly sexist in modern times. But that was the reality. We occasionally get an Empress Theodora or Catherine the Great or Queen Isabella or Empress Wu, but for most of history men ruled. There were reasons for this, and some of those are explored in the novel...