> One can easily put in 60+ hours for weeks on end and be incredibly productive while doing it.

Do you have an objective measure of that? I've worked with plenty of people who thought they were being productive for 60+ hours/week, but none of their productivity actually stacked up. Founder/CTO types were the worst, they'd bypass process and cause outages but because of their position everyone had to coddle their ego and pretend that they were doing good work and the trouble wasn't their fault.