That's just how companies do things sometimes. When a game flops that badly, someone needs to be fired or reassigned. It doesn't matter whether or not they did anything. They just need someone with a big spot on the credits to commit seppuku so that they can save face.

Even though he wasn't fired (obviously), and didn't actually lose very much, they made it feel like someone was punished for the mistake. He "took responsibility". That's all.