"From a business point of view, long hours by programmers are a key to profitability. A programmer probably needs to spend 25 hours per week...Thus a programmer who works 55 hours per week is twice as productive as one who works 40 hours per week.... A product is going to get out the door much faster if it is built by 4 people working 70-hour weeks (180 productive programmer-hours per week, after subtracting for 25 hours of coordination and structure comprehension time) than if by 12 people working 40-hour weeks (the same net of 180 hours per week)."
"If you see one of your best people walking out the door at 6:00 pm, try to think why you haven't challenged that person with an interesting project. If you see one of your average programmers walking out the door at 6:00 pm, recognize that this person is not developing into a good programmer."