There's simply no relation between the constant death-march described in this article and "practice" in the sense of personal improvement and skill-building. In fact, they're antithetical.
Even the strongest advocates of "practice makes perfect" doctrines, such as Anders Ericsson, talk about something called deliberate practice, which is an expertly designed regiment, requiring exhausting mental and physical effort, the close tutelage of a veteran teacher, and adequate rest periods for its positive effects to properly ripen.
These authors typically assess that even a top motivated and well-rested individual can only engage in "deliberate practice" for 4 hours daily at the very most.
So if you want to do that, then far from almost doubling the length of your workday, you should actually cut it in half, and ensure plentiful rest and light recreation before and after your workday. Basically, mimic the way top athletes train.
Otherwise, don't delude yourself that you are "practicing" or "improving". You're simply working, chugging along sub-optimally, doing what you already know without substantial improvement or room to grow or learn much.
These very same authors predict that by working a punishing 10-12+ hour daily schedule, your skills will not improve, and likely will deteriorate, since you will become deeply disengaged (cf The Power of Full Engagement).
The idea that perpetually over-worked, over-stressed, nearly-exhausted engineers are "practicing" or "improving themselves" is a romantic wishful-thinking with no basis in reality or scientific research.
Anecdotally, I've seen such places up close. Most people there burn out and/or move on quite quickly. Turnover in these companies tends to be very high, and they only keep those who can't find a better job.