Graham McNeill had a bit to say today on the Ultramari... sorry...GW website.
The fact that he had to create a character who doesn't think or act like your normal Smurf to make them interesting kinda shoots his own argument in the foot, but there you have it...Graham: I've written six novels (with more to come!) about the Ultramarines, and a question I've been asked a few times is, 'Why the Ultramarines? Why not pick an interesting Chapter?' That's a question that astounds me every time I hear it, as I look at the Ultramarines and think, why wouldn't I want to write about these guys? I've long had a bee in my bonnet about people thinking the Ultramarines are uninteresting, an irrational prejudice I think probably stems from the fact that the sons of Guilliman don't have any special abilities that allow them to bend the basic rules of the game. But fie upon you for such foolishness! If there's any one Chapter that best encapsulates what the Space Marines are, it's the Ultramarines.
The Space Marines were created to conquer the galaxy, to drive away hostile aliens and reunite the disparate strands of Mankind in one grand unification. A noble aim that, thanks to the treachery of one of the Emperor's sons, was snatched away just as it was within reach. In the slow stagnation that followed, the Adeptus Astartes (as they were now known) each fought on with their own interpretation of the Emperor's will to guide them. To my mind, the only Chapter to stay true to the Emperor's original plan was the Ultramarines. They're one of the few Chapters that recognise that they were created to serve Mankind. Their entire existence is predicated on the understanding that mortal humans are the true inheritors of the galaxy, not the Space Marines. It was for the ordinary men and women of the species that the Emperor began his Great Crusade, and the Space Marines were his instrument to achieve it.
In a galaxy of grim darkness, the Ultramarines are true heroes, warriors who fight to keep the Emperor's dream of unity alive. They are physically superior to mortals in almost every way, but where some Chapters keep an aloof distance between themselves and humans to the point where they can barely relate to them, the Ultramarines are part of the very fabric of the worlds they protect. Ultramar is, in microcosm, what the Imperium should be, and telling stories with proper Heroes is what really fires me up. I love to tell stories about a good anti-hero or villain as much as the next man, but that seems almost too easy. I prefer to tell stories that are the spots of illumination against the darkness, the tales where you can see the flickering, distant flame that is the light at the end of the tunnel. It's guttering and almost dead, but there's still hope it might not go out. And that's why I love writing about the Ultramarines; they're the Chapter that best embody that fragile hope's protectors. Without them to admire and inspire those around them, the Imperium is just a hellish nightmare from which you can't awaken. With them, it's a struggle that might, just might, be won someday.