I notice that people looking for character arcs and the like are looking in the DS9 part of the story. I think that part was setting up for the other 4 books. The Kira/Keev part is where the story of Revelation and Dust is, almost like Keev's story is Kira's "Far Beyond the Stars".
So your argument would be that RaD was about Keev. I'm not saying I disagree with you, because that storyline was the only complete arc in the book, but I have to play devil's advocate here.
If RaD was about Keev, how did the other 3/4 of the novel advance the plot? I don't see that the rest of the book has anything to do with the Keev story. If that is the case, it makes the book even worse under the criteria of its critics, not better. The other portions of the book, having no bearing on the Keev plot, would best be used in the other novels of The Fall
series in that case.
First, I'd say that the Kira/Keev part was more like 1/2 the novel than 1/4.
The other portions are setup for the rest of The Fall
- new DS9, Bacco, where are the characters now. Their character arcs are more character "a"s right now. The "r" and the "c" come in the later books, so their arcs are over the 5-book miniseries. And not every single bit of story is about advancing the plot - not every B-story is incredibly important.