There's a ton of conflation going on in the article. Most importantly, what defines "productive work" versus just "output" is not defined. He seems to focus on "academic" work but doesn't define terms well.
I've written about this here before, in summary:
1) Work has a cost to the endeavor too. Even with salaried workers.
2) If what you're doing can be boiled down to time-and-motion studies, you can always make cases where longer hours yield more "output". BUT pushing even these types of work beyond marginally has been found to incur large ongoing cost the mission. This is backed by research that has been done many times since WWII with thousands of subjects.
3) Then, what software developers do is NOT amenable to time-and-motion studies. So even the marginal increases in time working has an even greater case of dubious value.
I've written about this here before, in summary:
1) Work has a cost to the endeavor too. Even with salaried workers.
2) If what you're doing can be boiled down to time-and-motion studies, you can always make cases where longer hours yield more "output". BUT pushing even these types of work beyond marginally has been found to incur large ongoing cost the mission. This is backed by research that has been done many times since WWII with thousands of subjects.
3) Then, what software developers do is NOT amenable to time-and-motion studies. So even the marginal increases in time working has an even greater case of dubious value.