l think it is a remnant from the industrial age: 3× 8 hour shifts is 24 hrs of production. If you are producing something @X / hr that might make sense. But cognitive demanding work after 3-4 hours stops being productive : you are basically warming your chair : in aviation human error has been studied a long time and Human Performance factors are well understood : if you are fatigued you have the same mental performance or being legally drunk... Always makes me laugh when you hear these stories of lawyers or bankers doing 100 hr+ weeks : phsiologically they are functional idiots , their brains are fried, unless they are doing drugs which they probably are, these hours don't have 20 % of the work quality and the likelihood of serious errors climbs exponentially.
They are masters at window dressing though...
I agree. I always try to limit the amount of studying I do. I know my own limits. I cannot study during the night, and I cannot study the whole day. Pulling an all nighter is a no brainer. But I still see many people doing it. I don't know if people still do while working, but it makes no sense. Even though people seem to prefer it for some reason.