The problem with this title is that;
A) Too many of the cast are also prominently featured in other books (Wolverine, Iceman, Beast, Rachel, Quentin) that it makes what happens in this book seem slighter. The Planet Sin story holds not as much gravity for Quentin and Wolverine because of the similar and more heavy interaction in Alpha and Omega. Can't get as into the interactions in this book if they are not as significant as what is happening in the others.
B) The tone is so different from a typical "flagship" x-book that long time readers are confused by the shift and since UXM isn't very good right now that places extra burden of expectations on this title.
C) Nick Bradshaw does not fit the tone of this series... Aaron's ideas are too weird and out-there for his clean, cartoony, bright style. As difficult as Bachalo can be to understand in certain panels, his style fits this kind of story-telling nicely. Bradshaw does not belong on this title or any title when paired with Bachalo.
D) The Hellfire Club kids are not a good arch villains. In interviews, Aaron seems to think that their lack of credibility is the fault of the readers who are not willing to suspend disbelief enough to believe in these kids as super-villains. That is not true at all- what strains credulity is that these kids come out of nowhere to suddenly be as credible a threat to the X-Men as Apocalypse, Sinister, the Brotherhood etc... Aaron didn't build them up enough before (to borrow a wrestling term) giving them their "push."
This is how I sees it.