When I was with a startup during the dot com era, it seemed to me that the worker bees were on speed, while the executives were on coke. I could see what the worker bees were doing, but nothing else could explain the decisions made at the upper levels. The incentives were pretty obvious--long hours without sleep, and demand to be 'on' regardless of circumstance, and the arrogance that comes with mastering a small domain and thinking you've mastered everything (see Dunning-Kruger.)
Personally, when I was tired, what I craved was sleep. But that was frowned upon. You can see why so many did drugs.
Arrogance, though, is a major consideration. Notice the parent comment: If you take drugs and get addicted... but no one plans to get addicted. Oh, take drugs by all means, just don't get addicted. They take drugs to cope, and as they are masters of the universe, they could not possibly get addicted. Besides, it's just to meet this deadline... and the next... and the next...
The entire culture is a massive fuck-up. Tired people make mistakes, and mistakes cost money. In the 1850's they discovered that 40 hours a week was the sweet spot for productivity, and every generation since has had to discover the same thing the hard way. I cannot count the number of projects I have seen crash and burn because of this bullshit.
But fuck it. We're John Galt. We can do anything. Just another bump to get me through...
How's that working out?