The big picture is trivially true -- if you don't sleep, you die. Where's your favorite language, now? Similarly if you don't eat -- yet few people would make a rant about "food quality matters more than languages".<p>There's still a lot of nuance. What studies there are don't negate the existence of variability either. Well, then what's the point of bringing up the subject? Taken broadly sleep is important as life itself, but then it has no place in an earnest discussion around improving productivity. Taken narrowly, it's very context sensitive, so it's again rather useless in discussing improving your own or even your team's productivity unless you're already in the weeds of knowing individuals' detailed backgrounds.<p>There's a fun fact johnc's comment in that thread points out. We can all agree if we want that if people aren't getting their 8 hours (or some number close by), that has to happen first, and we can ignore whatever nuance/variability/context objections one might have. But with 8 hours, there are still over 100 other hours in the week. 80 if we're just talking M-F. What are you going to do to fill those more productively? If switching languages lets you do something in half the time as otherwise, why wouldn't you switch, and rather than just taking half the day off, <i>continue working</i> and do twice as much as you would in the other language for the day?<p>Is the point that you shouldn't unnecessarily waste your waking life for some company? Fine, but you shouldn't do that even if you're getting 10 hours every night and are only asked to work 30 hours a week if those 30 hours are truly a waste. On the other hand, you might be in a situation where 80+ hours this week (hopefully not forced to be compressed to M-F or intrude on your sleep requirements) spent on work is the most non-wasteful thing you can think to be doing with your life at this time. Circumstances are different.