My motto for these situation is, if it doesn't fit, cut it. Pushing deadlines back looks sloppy, and I take enough pride in my work that I want to take the time to make a quality product. I can always go back and add features later if they're important. I don't know much about American football, but I know most of the game is making plays to move a few yards. You basically keep pushing until the opportunity comes to make a pass that gets you to the end zone, and you need to keep make good plays so you don't turn over the ball. That's what software development feels like to me, pushing quality improvements to keep making yards until eventually you're in a position where you're one project away from shipping something big.
I like this analogy. A lot of time leaders get in a tough 4th-down situation, where they must make a big play, and so they tell the players to make the big play. If the players fail, that's the players fault, the coach will yell at them and that's that; right? Well, no. If a coach acted like that they'd be fired, so why do we accept the same from our business leaders?
