Who says there's not a logical reason? Bendis is capable of strong writing but as his star power has risen and he's juggled more and more books at a time, he seems content to have gotten a big head that prevents him from seeing his flaws and growing as a writer, and his weaknesses have bubled more clearly to the surface. IMO, these problems are grossly apparent in his x-books.
There's a lack of distinguishing voice between his characters, who all have a tendency to speak with the same rhythm. He uses this cadence as a crutch, and where it was once a vehicle for clever writing and as a means to convey story without being too expository, it's now more often than not an excuse to fill space. Someone compared his writing as a good fit because X-Men is "soap operatic", but the strength of the best soap operas is that they substitute a plot-driven approach for intensive characterization spread over a large canvas. That's largely absent here.
This. His style works fantastically for Alias and Daredevil. It doesn't work for other characters as much. It barely worked for New Avengers, and even then only some of the time.
Compare the difference in voice among characters he writes compared to, say, Joss Whedon.
But more problematic, for me, is that there isn't rhyme or reason to the plot that is there. Things happen because Bendis wants them to happen, not because they make sense in the context of the universe he's created.
But THIS is by far his worst flaw. So much of what he writes just makes no sense IN ITS OWN CONTEXT. I can't even remember the last time he wrote a sensical, satisfying ending to a story. Daredevil, maybe?
And I completely identify with not understanding why this book exists. It's exactly like Zombipanda said: Bendis just makes stuff happen to see what happens. This story isn't going anywhere, isn't answering any questions, and isn't identifying any problems that need solving. It reads exactly like a guy who wanted to write a What If story where the original X-Men meet the present-day X-Men, and he's stretching it out as long as he can. And I personally don't even find it interesting.