The fluff is most likely why the game has enjoyed popularity for so long. The interesting stories of the different races and mankind’s struggle to survive a universe that has grown awfully cluttered with dangers to their sovereignty that have necessitated apocalyptic measures just to defend, on battlefields as far reaching as Death worlds, Agriworlds and even the battle for your very soul.
Star Wars made Pseudo-mysticism and science fiction meld well and probably spawned a fair amount of these kinds of things, but few in the world can boast the popularity of the 40,000 universe.
So you would think, then, that the story would be sacrosanct, something to be protected and proud of. That of all the game elements, whether it be rules or artwork, the one thing they wouldn't change too substantially was the underlying story of the various factions. Advance the story? Sure. Most games do that. But utterly cast out all history and remake it? Are you not playing with fire and arguing with success at that point? I think you are.
That is just what has been done. In the newest codex's, instead of adding to the ongoing story, they have literally DELETED it in many places. Literally.
In the main rulebook which so many players will probably never own thanks to the overwhelming demand for the "mini-rulebook", you will find that seriously important story elements are simply gone. Vanished in fact. Gone is mention of the Exterminatus order on Tau. Gone is the mention of the fungi-origins of the Orks. Gone is the dominance of the Star Gods in Necron mythology and in practice. Gone is the entire history of the Grey Knights, replaced with the Men in Black image (and the retarded moniker of being the 666th Space Marine Legion, a drop of irony in a pool of tongue in cheek references that make it hard to take that seriously). Sisters of
The Dark Eldar codex was a tremendously well done book, and hope rose anew after that for fluff, but really, it's a disappointing spiral we are on. The Chaos Space marine codex and the Advanced ordering stuff looks promising and I am hopeful that it will be a return to glory for the somewhat... uninteresting codex that so many abandoned in disgust. Dark Angels appear to be close on their heels.
I just pray that when the dust settles, they won't turn Tau into amphibious creatures instead of the steppe hunters they've always been. But you never know...