Battlestar Galactica: The Final Season

I know the season isn’t over yet, but it might as well be. What the frak are they thinking or aren’t they? Four key members of the crew are Cylons, while others completely lose their focus and personalities; did the writers forget the characters’ motivation (over 99% of the humanity destroyed in a matter of hours and the rest are desperate refugees on the run and in hiding)? or the show’s plot (find a safe haven and rebuild)? Wasn’t that enough? Why throw it away for a nonsensical idea?