My biggest issues with the KJA books (I subjected myself to a few) was that they are so tonally different from Frank Herbert's work. Paul of Dune and the Winds of Dune kind of fill in some of the gaps and with a better writer could have been interesting additions. The books about the Butlerian Jihad were just awful though and I'm still pissed off about Hunters of Dune/Sandworms of Dune - supposedly based on Frank Herbert's notes for the conclusion of the story but it later came out those notes were about 2 paragraphs. I suspect the ending kind of is what was intended about the ultimate Kwisatz Haderach and maybe even the enemy, but the execution was so terrible that they ruined it.
Ser Scot A Ellison reacted to a post in a topic:
Dune. Book discussion. (Spoilers welcome) KJA’s fanfiction sucks… right?