The Problems Build
There are two major problems, though. The first is that the conflict between the X-Men and the Inhumans just feels rather artificial. It’s clearly one step short of trolling X-Men fans; many had long argued that the X-Men were being phased out in favor of the Inhumans. In setting up this controversial arc, Marvel chose controversy over consistency. Fans could see no reason why weather-manipulators couldn’t gather the Terrigen into one place and then contain it. This shouldn’t even cause a problem for the Inhumans; historically, the Inhumans had preferred the Terrigen to be contained in chambers, with Inhuman candidates stepping into the Mists as part of a sacred rite.
Inhumans vs. X-Men actually made this problem worse. The X-Men’s strategy for destroying the Terrigen was more than a little bemusing; Forge devised a machine that could gather all the Terrigen in one place, and the X-Men would then incinerate it. So the proposed fan-solution became even more persuasive, and the whole conflict lost meaning as a result.
The second problem is tied to this. The post-Secret Wars comics had discussed Cyclops as a genocidal monster, and had literally compared him to Adolf Hitler. Worse still, those comparisons had been made both by X-Men and Inhumans; the idea has been a constant refrain in Dennis Hopeless’s All-New X-Men. References had been made to Inhumans dying at Cyclops’s hands. But Death of X didn’t reveal anything genocidal; Cyclops (apparently) destroyed half the world’s Terrigen in a single strike, and Black Bolt responded with an apparent act of murder.
To compare an act of self-preservation, in which Cyclops destroyed half the Terrigen Mists, to Adolf Hitler and the Holocaust seems more than a little overstated. That’s particularly the case when fans could easily see a solution to the conflict, one that didn’t lead to one of the two races being rendered extinct.