Really it comes down to the simple fact that for the most part programmers happily sign a contract saying they will work X hours for Y money. If they are 'productive' they then can move up in the company and be a manager, but still for X and Y++. Sales guys are paid in a completely different way, same with the stock holders (founders etc). It doesn't matter how productive you are, even if you complete the task in 1 hour and have the rest of the week to do nothing, you agreed to work 40 so your boss will give you something new to do.