I don't think it needed to backfire and I think they did very well for the most part. It seems that DC does very well with the whole continuity thing when it's not directly addressing the multiverse or reality altering characters. But when you try to do things like Zero Hour, Infinite Crisis, Final Crisis, Legion of 3 Worlds, Flash: Rebirth and from the sound of it, Flashpoint, you run into trouble. The end up doing things that the Crisis was designed to prevent. It doesn't help that they've hired writers who get off to continuity porn.