So, with the past ten years of departures from Capcom, you can kind of start putting together a possible narrative for what game design is like there.
The people who were there because they wanted to make games and not business decisions (your Mikamis, your Kamiyas), eventually get tired of their input not being taken with their games, even after they made major successes. Those that didn't leave moved up (like Inafune or Ono) and they still had relatively little input on things that moved forward, but were required to act as a brick wall to people like Mikami and Kamiya. Eventually Inafune got beaten down enough by the process that he quit (and had a tell-all interview where he described now hellish working there can be) and I imagine Ono is feeling the same grind. He wants to do more, he just can't.
It seems like the people who are made in to producers eventually just lose their passion because they're never going to get what they want, but have to be in a position of telling everyone below them to fuck off.