Comment by fatbird

The Bene Gesserit and the Spacing Guild were also a result of the Butlerian Jihad. All three started as schools of human development in the absence of powerful technology.

Also, Herbert's point about dependence on machines creating machine-dependent humans, trapped in a deterministic arc of evolution, feeds into his larger themes about open-ended evolution and its arms-race. It's not just a throwaway backstory.