To some degree, yes. Gailey can wring production out of a turnip. While that is good, who wants to walk into a gun fight with a loaded turnip?
Suppose instead that Gailey insisted on getting great offensive talent out of the draft, etc. Suppose the Bills could decide to ground and pound it, throw every down, or whatever they wanted and actually execute the offense du jour well? It opens up the playbook. It takes some pressure off. It lets them control the tempo of the game a bit. Instead, the Bills spend most of their time and resources waffling back and forth on the defensive side of the ball and have a guy that can't coach his way out of a paper bag running that side of the show.