Some new details/rumors surrounding the ouster of of Marvel CEO Ike Perlmutter and his Marvel Comics creative committee have come to light that state the reason for the dismissal was the failure of Avengers: Age Of Ultron.
Quick recap: Marvel Studios president and producer Kevin Feige has moved Marvel Studios away from Perlmutter and the comics and TV divisions of Marvel, and more into the Disney fold, which also saw the end of the Marvel Creative Committee (Quesada, Bendis, Buckley).
Now Bleeding Cool is stating a big reason for Feige booting them out is because Disney feels Avengers: Age Of Ultron was a failure due to not making as much money as the first movie and not as good reviews. While the difference was only around $100 million, it's suggested Disney was disappointed people didn't go back for second viewings. Internationally, Avengers 2 did better than the first movie, but here in the U.S. saw an almost $200 million drop. I'm guessing Disney expected Avengers 2 to do better than the first at the box office (especially considering how big a factor foreign audiences have become).
It's said Feige used the "failure" of Avengers 2 as leverage to get rid of Perlmutter and the Creative Committee, which according to the report, was disbanded a few months ago (and may signal they are not as involved with Captain America: Civil War and Doctor Strange).
My two cents regarding Avengers 2 being a "failure," I would have to agree as I was really disappointed with the movie. I wasn't a big fan of how they portrayed Ultron, and I also felt they didn't give Whedon a lot of creative freedom (as a lot of his stuff was cut). I can recall an interview with Whedon from a while back where it sounded as if Avengers: Age Of Ultron would be an Empire Strikes Back; however, I think we can all agree, Avengers 2 can't even compare. Whedon said he was going to "twist the knife" and "dig a little deeper" with the sequel, which I don't think the movie came close to doing at all.