AVENGERS is the center of the Marvel Universe, the place where all other roads intersects. So it’s natural and proper that it will be at the center of most Marvel Universe events. Meanwhile, in the span of time you’re talking about, there have been a number of X-MEN Events stemming from Brian’s work over there–again, which is consistent with the past. In the history of Marvel, how many line-wide events stemmed from the world of X-MEN? Onslaught, certainly, but that’s about it. (You could claim Mutant Massacre, and I might even be able to be convinced, but that seems to me to be something more akin to Black Vortex, in that it touches on a few books beyond the core, but not many.)