Moore was released because McCarthy wanted to call the plays. It's as simple as that. Some coaches call plays, some don't. There's no guarantee that Schottenheimer, if he's even hired, will call plays. He might, he might not.
Understood, but Jori Epstein was not talking about Kellen Moore. You are correct McCarthy wanted to call the plays but it is common practice for offensive coordinators to call plays. Not always but usually.
As such, McCarthy had more confidence in his ability to call plays than in his offensive coordinator's ability. That observation is irrefutable. If a
coordinator cannot be tasked with the responsibility of their position...
...a task and responsibility which offensive coordinator Kellen Moore was released from doing...
...the lack of responsibility should be a consideration when hiring a coach for a more responsible position.
Evidence.