How do you square this sort of mindset with the well-known demands of entrepreneurship?Because the 'well-known demands' are mostly socially constructed myths rather than reality. Because people are really bad at tracking stuff-done and find tracking hours-worked and looking at stuff-to-do much easier to think about. Because people a really fucking awful at figuring out how productive they are.
I have been a team coach multiple times where I have demonstrated by, weirdly, actually tracking the amount of work done that teams working fewer hours were producing more work. The amount of push back from these sorts of results from management and the team is incredible.
People know that if they only stayed a bit later they would get more done despite lots of evidence, by our tracking stories completed, bug reports, user satisfaction, etc. all went down the more hours people worked.
Tired people make mistakes. Tired people work slowly. You can be tired without 'feeling' tired. In anything but the very short term (and I'm talking days, maybe a week or two tops) trying to do hard intellectual, creative work for more than 30-40 hours a week will make you slower overall - not faster.
Hell - Ford promoted the 40 hour week as the maximum productivity point for physical labour on a production line... and we somehow imagine that working 60 hour weeks is going to make us do more.
People still seem to conceptualise 60 hour weeks as 40 normal hours + 20 extra. In fact it's 60 hours of being knackered where you're probably being half as productive as you would be if you were fully rested - but you're too damn tired to realise it.