I don't suppose they've waited for me to say so, but there is something about Alan Moore's writing at his (which excludes most recent stuff) that makes it impossible not to speak of genius.  He is not, of course, the first cartoonist whose brilliance forced admiration and recognition; from Jack Kirby to Giles to Benito Iacovitti, the number of cartoonists who have gained the name of genius from a dull and unconcerned world is surely in double figures.

However, the way Moore's genius imposes itself on readers is not like that of others.  I am not sure that I can put my finger on it, but there is something self-conscious about his writing, which yet does not take away from the impact.  One passage where I felt his peculiar touch particularly strongly is the foreshadowing of Sung Li's death in Top Ten #8, p.11.  This is not subtle; it is the very reverse of subtle.  Moore not only tells us that Sung Li dies in that video game; not only that she dies in every possible permutation of the game; but he takes some time - Moore points our attention to the game over three panels, nearly suspending the main action.  I don't think that any reader from that point on is going to be in doubt about poor Girl One's fate.  There is something about it of forcing the card on the reader, demanding them to pay attention to the literary device - foreshadowing - almost for its own sake.

It works, primarily, because Moore is exceptionally good at the payoff passage.  The death of Sung Li is shown with a minimum of verbiage and a maximum of emotion.  Captain Traynor makes up our minds for us in five words: "My God, that sweet girl..."  Irma's literally atomic rage and Jeff Smax' "Permission to use extreme force?" reflect the reaction of every reader: go get the bitch, go get the monster who killed one of her own for the sake of a rotten drug habit.  Secondarily, the evident use of the literary device also serves to distract the reader from the really significant development on the next page (I am speaking of #8): Commissioner Ultima's announcement of her inspection.  Had Moore not practically told us that Sung Li was doomed, more of us might have paid attention to this unexpected development and perhaps tied it up with the ghastly misadventures of King Peacock in Nova Roma in #9.  As it is, Ultima's villainy comes as a complete surprise, and the element of surprise and betrayal in the super-cops' rage is felt by every reader.

So I would suggest that Moore's secret is a delicate balance of carefully measured literary devices, drawing attention to the literary and even artificial nature of storytelling, with well-developed and emotionally basic impact climaxes.  It is still the raw, natural emotion that hooks us on his best writing; but the literariness tends to work to increase it.