People are not robots. If I'm worth $200 an hour for the first 5 hours to an employee, by the 16th straight hour I'm barely in the positive territory. Companies should STFU and pay more, their earnings and cash piles show that money is being made.
The truth is workplaces that limit distractions are much better places to work, and more enjoyable for employees. I've run organizations that offered one person offices to every developer, and it was a big reason why our turnover was extremely low.
Irrelevant. How do you know know I'm not already doing that.
My main point, which will valid for as long as humans are are the switch is that you cannot maximize every second.
And it's not about maximizing every second. It's about providing the best possible work environment to allow people to be more productive.