My personal opinion is that many people fail to see how much time they are wasting, and that that should be the primary reason to work less, not to work more. I've been tracking my work time pretty diligently for the better part of the last eighteen months. Here's my work stats:
I don't get paid for the hours I make, nor for overtime, as an intentional policy to prevent a work-skewed balance like what's so common in the US. I also have the freedom to work less as long as I get the work done. So I've noticed that weeks where I go over 40 hrs/wk of actual work (excluding commute and days off, including working at home) are draining, and weeks where i work less than 32 I start to feel bad about not working enough, even though it is often for a reason.
The above are also real hours, not rounded-up-consultancy hours, which is 9% more as per my tracking. Of the above time, 31% is directly billable, 24% is R&D, 11% is value-adding-but-not-billable and the remaining 34% is informal (eg lunch) or wasted time. Cal Newport posits in Deep Work that people can't (and shouldn't) do more than about 3-4 hours of focused, value-creating work, and it's been my goal to hit that on as many days as I can while minimizing wasted time. So far I'd say it's going great.
This is a discussion worth having but the Inc. article is spurious as hell.
Maybe this isn't the discussion you think is worth having here, but I felt like my n=1 is about as representative as the Inc. researches.