In professional football, there have always been coaches who win games, and coaches who win championships. Far rarer are the ones who become part of the country’s cultural furniture — figures so distinctive that decades later people still dress up as them, talk in their accents, and treat their scowls as a kind of civic inheritance. Mike Ditka, the former Chicago Bears tight end and coach who died on Oct. 9 at 86, was one of those. He was not the winningest coach in NFL history, nor the most tactically inventive. But he was by far the most iconic.