I think the contemporary startup idea that people have to be "working and playing" at the office for 10-14 hours a day to make anything significant happen is at worst, misguided, and, to a cynic like me, just a way to grind people out of your company before they can vest any significant amount of equity.
Kidding.
I'm not completely disparaging the long workday and loads of perks to keep you at the office. It is nice to have good food nearby most hours of the day, and amenities such as gyms help coalesce my time at the office around the "productive" part of my day. Where it falls apart is when managers have to justify their employees' work: even if the 6hr worker and the 10hr worker are equally productive, they're going to point to the 10 every time to justify their employees' salary and their own ability of a manager to get more out of them. Then the 6hr worker is asked to stay later for "team morale," which often amounts to little more than twiddling thumbs and waiting out the clock, with hopefully some of that time spent wondering why they're even there in the first place.
Also, fuck people asking you to stay for "team morale". If you left earlier, I'd think "If I worked harder, maybe they would let me leave earlier, too..."
I (and others) anecdotally lose steam part way through the day. The last couple hours are a waste. I see no reason why that would happen earlier if the day ended earlier.
Reason why ER nurses work 12 is continuance of care. You're better off being looked after by 2 shifts who are familiar with your case rather than 3 or 4. More people just add complexity
Also, I can't see how 6hours would mean no stretch/brain breaks.
"Exempt" workers, which is most of us in the tech industry, are paid a salary and have essentially no limit to the hours that may be asked of us.
You may be asked, but do you really have to accept? (I'm asking from Europe) It sounds insane to sell 24 of your hours per day for any typical salary?
1. Abolish "At-will" employment and replace it with "Just Cause". This will bring the US in line with the rest of the developed world.
2. Implement working time restrictions similar to the European Working Time Directive for both exempt, and non-exempt employees.
We have been in a race to the bottom with regard to labor law over the last 30 years.