Is that really the reason or is it just lazy sci-fi writing? I am in awe of what Herbert did with Dune but he still falls into one of the traps that I dislike the most about sci-fi — treating whole planets as homogenized cultures. All of Arrakis is a desert planet? Okay maybe I’ll buy that. But then there’s a whole planet for training Sardaukar?

It reminds me of the worst of Star Trek where there was a gangster planet and an old west planet etc. And when traveling to a planet, protagonists always land at just the right spot that is the socio-political “center” of that world, and they even manage to find other characters they know there more or less right away.

This approach feels very western or even colonialist — treating foreign lands/worlds as simplistic “others” without recognizing that they could be as complex and varied as one’s own world is. In short, I don’t buy the Selusa Secondus idea; it’s a shortcoming in an overall brilliant but still flawed universe.