The true productivity benefit from going into business for yourself is not that you can put in more effort. The human capacity for productive work is not that flexible, because we are not machines. The real multiplier is that you can direct your effort at that which truly matters. Most businesses spend 10% of their budget on 90% of their value. If you can work smarter you can get dramatically more done because you are building that which truly matters. That is where the PG article is right.
But, here's the problem with what I'm saying: people working crazy hours succeed. Everyone can see that. How can that be explained? In my opinion, those people succeed despite those hours, not because of them. It is their laser-like focus on reaching a goal that makes them succeed, but it is also this focus which makes them put in more hours thinking it brings success home sooner. It don't think it does, but it's almost impossible to prove it doesn't because there just aren't many places where highly passionate and focused people stick religiously to a 40 hour work schedule.
You can't simply put typical workers on a schedule that's twice as long and expect more productivity, that's true. Individually, though, you can normally become extraordinarily more productive if you have the right motivation.
people working crazy hours succeed.
Why is this such a mystery? Haven't you ever thrown yourselves into a new startup or idea and spent every waking hour on it for long periods of time because you were excited by what you were doing and it didn't feel like you were working? Haven't you ever gone to sleep thinking about your ideas, and jumped out of bed right away the next morning like a kid on Christmas and then worked on those ideas, barely wanting to take time to eat, at last breaking away from what you're working on late at night because you know you need to get some sleep?
Maybe it's a gene that allows some people to go into that mode. Maybe it's just a matter of finding the right motivation. Regardless, it appears that people who don't experience it can't understand it any more than blind people can really appreciate colors.
I then had to spend the next several days fixing all the damn bugs I'd put in because I wasn't thinking straight.