Unfortunately, it's all too obvious why Paramount had the book scuttled. Piller's scrupulous honesty doesn't paint Stewart or Spiner in a particularly flattering light, and, even though he's diplomatic about it, the story of his forced departure from Voyager makes several then-current Paramount employees look like a bunch of spoiled brats.
I disagree. Stewart was basically had two goals 1) Have Picard NOT brood for 90 minutes. 2) Keep it "sexy" i.e. not stiff and high on itself 3) Do NOT retread on old episodes.
Spiner just picked off plot-hole after plot hole, and questioned why should anyone care about the stuff that wasn't a hole.
If anything, I think the problem was keeping it as an action movie. ST can cross into other things besides action. Keep the mystery. An "Indiana Jones in space" would've been interesting. Make it a suspense-thriller. It's a big universe, it has room for more than one type of story, just like the real world does.
So if you're going to fault people, I'd lay that at the writer, producer, and a lesser extent, director being unable to go an entirely new direction. Having said that, INS was okay. Better than GEN, at least less boring than GEN (save for the first act).