If what naturally develops is not as effective as something else, I would like to think that people would eventually stop doing it.
As I mentioned (and as the links demonstrate) 80 hour work weeks don't double productivity in the long term. They may double the perception of productivity, and they may satisfy one's sense of urgency by never giving time to think, but I have never seen any evidence that they double productivity in the creation of software.
I don't particularly care for what links demonstrate, but I'm sure that people who are forced to work 80-hour schedule are very far from being twice as productive. However having worked under the 80-hour routine myself on my own project for two years I can assure you that it sure as hell helped to achieve a lot more and a lot faster. It's really a matter of motivation. Will I do it again? No ...but then I don't really need to now.
I'm happy to agree that you perceived higher productivity. But there's an open question whether it was more than perception. Tired people, for example, think they can drive much better than they can. A comedy staple is the non-fine person shouting, "I'm fine!"
I believe that for certain sorts of work, 80-hour weeks might be more productive than 40-hour weeks. E.g., digging ditches (at least for the very young and very healthy). But in software the costs of error are so high, and so hard to trace back, that it will take very solid studies to convince me that the increased error rates from long hours really are counterbalanced by the large number of hours put in.
As I mentioned (and as the links demonstrate) 80 hour work weeks don't double productivity in the long term. They may double the perception of productivity, and they may satisfy one's sense of urgency by never giving time to think, but I have never seen any evidence that they double productivity in the creation of software.