Ars Technica has a series on the history of the Amiga right now, and part 3 contained this:
Why was everybody willing to work so hard, to put in tons of late (and sometimes sleepless) nights just to build a new computer? The above and beyond dedication of high-tech workers has been a constant ever since Silicon Valley became Silicon Valley. Companies have often reaped the rewards from workers who were willing to put in hundreds of hours of unpaid overtime each month. Managers in other industries must look at these computer companies and wonder why they can’t get their workers to put in that kind of effort.
Part of the answer lies with the extreme, nearly autistic levels of concentration that are achieved by hardware and software engineers when they are working at peak efficiency. Everyday concerns like eating, sleeping, and personal hygiene often fade into the background when an engineer is in “the zone.” However, I think it goes beyond that simple explanation. Employees at small computer companies have a special position that even other engineers can’t hope to achieve. They get to make important technical decisions that have far-reaching effects on the entire industry. Often, they invent new techniques or ideas that significantly change the way people interact with their computers. Giving this kind of power and authority to ordinary employees is intoxicating; it makes people excited about the work that they do, and this excitement then propels them to achieve more and work faster than they ever thought they could.
The reason this works (and the reason why you also have those tendencies in what is often referred to as “creative” jobs) is simply that the worker is not (or at least less) alienated from their work:
The theoretic basis of alienation, within the capitalist mode of production, is that the worker invariably loses the ability to determine life and destiny, when deprived of the right to think (conceive) of themselves as the director of their own actions; to determine the character of said actions; to define relationships with other people; and to own those items of value from goods and services, produced by their own labour. Although the worker is an autonomous, self-realized human being, as an economic entity, this worker is directed to goals and diverted to activities that are dictated by the bourgeoisie, who own the means of production, in order to extract from the worker the maximum amount of surplus value, in the course of business competition among industrialists.