Two years after asking to be held accountable if his San Francisco 49ers fall short of winning the Super Bowl, team CEO Jed York was back on stage having fired two more coaches, a general manager, and seen his team post a 7-25 record. York apologized Monday for a 2-14 record this season that he called embarrassing, and repeatedly said the organization needed a “clean slate” in order to re-establish a “championship culture.”