Of course everyone has a point where working another hour is not a good deal. But if that varies from person to person as much as other things do, it would be very convenient for a startup founder to be a couple standard deviations above the mean.
Probably 10-20% of the people on the dev team just loved it. They couldn't get enough. That includes engineers and artists. They could work from 9am to 11pm for months.
But then management expects 100% of people to be like that. And there's peer pressure not to let down your coworkers. But in reality some people just have more stamina, and can get more done with the incremental hour, while for others it was just clocking time and being a zombie.
I definitely couldn't get much more done in all those late nights, although it in part it has to do with the fact that there was some sort of "schedule". If you know that you can take a day or 2 off whenever you want, you're likely to have more stamina for a 16 hour bender.
Anyway, there is so much human variation in other things; it doesn't surprise me at all that it's true for how many hours you can productively work in a day. I would bet startup founders need that stamina, although I'm sure there are many more components to success.
Now, the same cant be said about writing TPS reports.
So bottom line is that it's futile for management to push people that hard. Some people love the problem and they'll put tremendous hours int oit. But you can't force that upon anyone.
On the other hand, perversely, I can see the logic to it. There are 20% of people who are running full stream and being super productive for 14 hours a day. Maybe you just keep everybody in the office so that those people feel like everyone is making a sacrifice too? If you don't care about burning people out, I guess it is rational to keep people in the office if only 20% of people get more work done, if those 20% would leave if everyone wasn't there.
Now, imagine the same hours on someone else's tasks and according to an inflexible schedule. Would it be the same? I think not. I imagine that is what you meant by 'grinding'.
A few nights ago,I got jazzed-up on the Vietnamese Iced Coffee I'd had with dinner, and I literally coded all night and into the daylight. I probably started around 8PM and ended around 9AM, working on my hobby project.
And honestly, if I hadn't been jazzed up, I would have stopped somewhere around 1:30AM, to my own great benefit. By the end I was spending half my available effort just staying awake and remembering how my code is broadly structured.
If I'd had to do something other than cycle through compile-run-debug, I would have failed completely. No matter your caffeine or passion levels, at some point you lose sanity points and Cthulhu arises from the depths to eat your code and then your soul.
All management that I've seen dislikes people with 'distinction', 'rock stars', 'mavericks'... The reason is they make rewards inevitable.
The cult of management likes to believe in comparative rewarding. Its believed if all are same, no one deserves a reward.
Besides I've met a few managers who mark awesome performances as just 'meets expectations' because they expected you to be awesome and you were just that. So no reward for you.
Management survives on averaging and normalizing people efforts to minimize giving away of rewards.
My experience through various sectors of the software industry (including gaming) is that virtually nobody really works 9 am to 11pm for months. But some people are happy being at the office from 9 am to 11 pm assuming the "work day" includes a multi-hour team lunch break, some random breaks for playing Doom II, Diablo 3 or the newest Battlefield or whatever is hot at the office, lots of slashdotting/redditing/HNing/etc, hours long discussions about what happened on the hot geeky tv show, etc. So what it comes down to isn't even the workaholics vs the non-workaholics, but the totally tech-focused geeks vs the people who have non-tech things going on in their lives.
FWIW, up until my early-mid 30s I was very much the former, so I don't entirely begrudge that lifestyle, but I think it is mostly fantasy that those people are putting in significantly more actual work hours than the other group. Personally, I know I'm vastly more productive putting in 8-ish hours day now than I ever was when I was putting in 16-ish hour "work" days, though everyone's mileage may vary.
That said, there was lots of downtime, mainly for people whose brains were burnt like mine. Never multi hour lunches though.
It would be surprising if on a talented team there simply weren't people who had much more stamina than others, or just enjoyed their work much more. I'm not saying there's something to be glorified or emulated there.
But how long did they keep this up for? Months-long crunch times popping up for, what, 5 years? Or did they keep this up for 10, 20 years? Burnout and health effects can take years to show up.
I suspect those that do this and keep up the pace move on to more organizational work later on, which isn't the same thing.
Lots of people leave the game industry like me, but there were definitely those who did it for 10 years straight.
Edit: Found it.
http://news.ycombinator.com/item?id=209195
7 hours was his personal max, 4-5 hours was his personal average, 10 hours was more than anyone in the group ever spent coding.
For example, at one point in my life I worked 8-hour office days and 8-hour evenings as a bartender. I was astonished to discover I could do this for months without getting exhausted at all, because they used completely different parts of my brains, with virtually zero overlap. Office work was intellectual, bar work was physical and social.
I personally can't do truly effective, intellectual coding for more than about four hours in a day. After that, it exhausts me. But I can happily deal with meetings, or project management, or marketing or whatnot. So because startup founders can often divide their time up into blocks of entirely different tasks, it makes sense they can work effectively over longer hours.
Note, I'm not talking about being interrupted all the time, though -- I'm talking about 4 hours of coding, 4 hours of meeting, 2 hours of product, 4 hours of marketing.
One hour you could be writing code, the next answering a support email, the next pitching a prospective customer, and so on. It could be that by switching gears every few hours, people are able to retain some of their productivity.
e.g. If I were doing nothing but customer contact mode, I know that I can send 50 emails in a day of moderate complexity. (e.g. Consulting mini-proposal for a client, support issue for BCC customer, pre-sales question for AR, ... x50. I know this because I have verifiably done it on e.g. launch days before.)
I did four things today -- video recording, hopped on a call, sent emails, and... shoot, only three things but I thought I remembered four. My subjective experience is that 1/3rd of my day was email. How many emails did I send? 1/3 * 50 = ~15? No. Five. And it (subjectively) felt like pulling teeth even though three of those were the same email with a few hand-written edits in the middle of them, whereas after I get into email flow mode for I can normally do two hours without getting bored.
I've got at least two hours into working with video today. How many 5 minute videos have I completed? Umm, zero.
Contrast this with yesterday: yesterday I putzed around to 6 PM and then coded until 10 PM then quit for dinner. I got two features coded and tested then squashed a pair of bugs. Yesterday feels non-productive in some ineffable way ("I putzed around until 6 PM! I only worked 4 hours and my salaryman brain rebels against the sheer laxity! All I did was code six measly little commits!") but it almost certainly added more to the business.
This is the superman myth, it doesn't exist.
If Bob, our intrepid entrepreneur, actually worked 40 hours a week he wouldn't spend so much time faffing. The 'busy work' disappears. Overall productivity drops the more you work long hours.
I've nowhere near your experience with entrepreneurs, I totally admit, but one of the symptoms I've noticed in crunch entrepreneurs is their mental diarrhoea, they take 15-20 minutes rambling on talking to you about a decision you've asked for that they normally would have made in a minute or 2. You start walking away and then suddenly they have another point/thought. They're mentally exhausted. I can reflect back on myself and see the same thing when I was doing crazy hours.
Some of these people have succeeded, some haven't.
But the person them self doesn't notice. They still think they are operating at high productivity.
[Edit] As a result, they see high productivity, but do not see the focus shift. Staying on task is what is important in crunch mode, and there may be some utility to founders that have more tasks (and thus goals) in shifting focus, but larger organizations suffer from defocusing, task shifting, and worker collisions.
I know people can work many more than 40 productive hours a week for years at a time because I did it myself during Viaweb. I know lots of YC founders who do as well.
I also know from my own experience that this ability varies between people. I can't work the hours now at 47 that I could at 30.
Why shouldn't ability to work vary among humans? Practically every other ability does.
Isn't it the case that they can do more in the same amount of time, not work longer? Either way it's a net win, but I don't think you need superpowers to be successful.
Incidentally: in your essays (which I enjoy), you often imply that founders should work long hours. If founders working long hours actually decreases the likelihood of a startup succeeding, then you've been giving bad advice for many years now. (And I'm sure that people have been taking it.) That's something that you should think seriously about.
Is it?
When you run a spreadsheet and scatter plot hours worked over the first few months against your ROI on startups, do you see a meaningful correlation?
I say "first few months" because once a startup is successful, the founders are almost always going to put in more hours than those that languish in obscurity.
As a software engineer I exactly notice the things the article mentions. After 6-7 hours I'm getting tired and after 8 hours it becomes really hard to concentrate.
I think everyone has experienced extreme bursts of productivity at some point where they think "If I could keep this up: I could work just 3 months a year / complete a degree in 6 months / build this thing in a 3 weeks." The differences between average and awesome, for the same person, are huge.
My guess is that the people who can consistently keep their productivity at the far end of the spectrum are there because of a combination factors, but I am really just guessing.
Lots of people with a 40 hour work week go home to play a computer game for several hours a night. If your work was as much fun as playing a computer game you would have no problem working 10 hours a day. Startup work might be just as much fun as computer games?