Developer estimates are regularly off because "experienced development managers" are all too eager and willing to allow organizational politics and external influences to add complexity in ways the developers cannot anticipate. Inexperienced developers' estimates are even further off because of their relative lack of experience.
I assure you, the first time a "development manager" tries to scapegoat his subordinates for his own failures to deliver to these external influences his subordinates realize that their estimates impact them eventually, and directly.
Developer estimates are regularly off because "experienced development managers" are all too eager and willing to allow organizational politics and external influences to add complexity in ways the developers cannot anticipate. Inexperienced developers' estimates are even further off because of their relative lack of experience.
I assure you, the first time a "development manager" tries to scapegoat his subordinates for his own failures to deliver to these external influences his subordinates realize that their estimates impact them eventually, and directly.