Having spend the last decade living the startup life, and now searching for something more stable, I have to say you're setting up a false dichotomy between pas

Having spend the last decade living the startup life, and now searching for something more stable, I have to say you're setting up a false dichotomy between passionate and balance-seeking. They are completely orthogonal, you can be passionate and work widely varying hours; you can also be indifferent and work widely varying hours. On a tangent, I don't really like the word passion anyway. What makes me a good programmer is not my passion for it, it's my curiosity and motivation. My motivation is a primary factor in my performance, and that probably is 80% influenced by context, and 20% by the content of the task itself (at least for most things that fall within the standard purview of programming tasks). Finally, you don't mention talent for the new graduate. That is a huge factor. If the new grad is not extremely talented, they will never produce anything of value. If they are highly talented they can likely power through a lot of things, but they also need to make good decisions about what to work on since time allocation is the single hardest thing about getting early traction for a startup. Yes, all else being equal, take the guy that wants to work 16 hours a day and has no other distractions, but if the veteran who wants to work 30 hours a week has better business sense and a smarter idea of what to build and when, then that dwarfs the code quality consideration.