Which is why Chevy Chase's complaint of "It’s just a f*cking mediocre sitcom!" is so cutting. This probably reflects the studio-logic that saw no reason not to remove Harmon as showrunner. In fact, as he explained on his tumblr account, he was not even contacted to say he had been fired!
Why’d Sony want me gone? I can’t answer that because I’ve been in as much contact with them as you have. They literally haven’t called me since the season four pickup, so their reasons for replacing me are clearly none of my business. Community is their property, I only own ten percent of it, and I kind of don’t want to hear what their complaints are because I’m sure it would hurt my feelings even more now that I’d be listening for free.