Note: These are non-founder/co-founder hours.
But really, in order for it to happen, the developers need to allow themselves to be walked over. Sadly, "being walked over" is a common skill in your average dev, while "not being walked over" is rare. All it takes is one guy to stand up for the team though, and sanity will prevail.
I've been that guy on occasion. Developer Employee #1 at a newly funded startup, I sat in a meeting the first week where the CTO laid out a rough timeline and the CEO said something along the lines of "these are 60 hour weeks we're talking about, right?". Amazingly, the CTO didn't immediately say "of course not". So I did.
To my knowledge, no developer ever worked more than 40 hours in a single week while I was there.
However usually those company's prefer the greener type of employee who is willing to take this kind of abuse. Get a Salaried position and they whip and beat you to get the work out of you.
President, CTO's can generally spend a lot of time working in order to keep everything going.
40 hour work week is the LAW in the US FYI; if they are asking you to work 65 hours a week and you are salaried. You are entitled to overtime pay.
Employers love it when employee's don't know the law; it allows them to get away with not paying them overtime when they are legally entitled.
Unfortunately I don't know the US federal and state laws, so I can't really tell you if you're right :) but I can tell you that in the rest of the western world, 40 hours (or even less) are law for everyone, including CEO, CTO and whatever C level you throw at it. Anything after that has to be paid overtime or you're breaking the law.
The shepherds will be brutal as long as the sheep are docile.
http://www.labour.gov.on.ca/english/es/tools/srt/coverage_go...
http://www.ontario.ca/laws/regulation/010285#BK17
(I haven't found definitive answers for other provinces.)
Edit: spelling
The US is way behind the curve when compared to other developed countries. I'd like to see the FSLA updated to the same level of protection as the EU Working Time Directive.
http://www.dir.ca.gov/dlse/Glossary.asp?Button1=E#employee%2...
Firstly yes it does happen, it happened at my startup and others that I know.
Secondly, it is an indicator of how inexperienced the team (and management) at the startup are.
Research has shown that knowledge workers spend typically less than 20 hours a week doing actual productive work, and beyond that it's ass in seat time (read Peopleware).
It is somewhat counter intuitive but often (not always) the way to launch (or whatever your goal) is to work less hours not more. My last gig (which required considerable programming skill) only needed me to spend 4-6 hours a day to get a prototype of a truly innovative product.
Most good senior developers don't do more than 40 hour weeks and most good managers + CTOs don't ask for it because they know it hinders, not helps.
Junior devs often do it because they don't know better and inexperienced management encourage it because they think more work hours == more work (flat out wrong).
Finally one of the reasons why this may be the case is it (a)is what startups to (b) looks good to investors.