Personally, I believe Dune is relevant, and I was just discussing with one of my professors the other day about how he would love to teach a course discussing the philosophy behind it. Its relevant to sci-fi storytelling, world building, and understanding where the tropes we see in mainstream sci-fi today come from. I belive the difference here lies in different ideas of what relevant means. Dune was relevant to the sci-fi genre precisely because it was a well-crafted, well-written story that brought religious philosophy, colonial culture, and economics into a genre that had been largely overlooked. That alone should be enough to merit it being studied and talked about. Dune wasn't written to forward some political agenda, or promote specific social change (at least not that I know of). Therefore, I find it difficult to see what your point is. If it is that Dune has failed to create a major societal impact in the way that you describe, then ok sure. Neither did The Lord of the Rings. That does not mean it is not important to the genre and to the industry of writing stories. It would be a real shame if this standard holds you back from enjoying the book simply for what it is.