I'm going to go out on a limb and say the bigger problem with 40-50 hour per week obligations is that it doesn't leave you free to work 80 hour weeks.
A lot of startups really aren't doing anything that technically exceptional, but if you want someone to spend their evenings fixing bugs in your bog-standard Rails app, it's much easier to persuade the guy that spends them fixing bugs in bleeding edge javascript frameworks than the guy that spends them with his wife and kids.
A lot of startups really aren't doing anything that technically exceptional, but if you want someone to spend their evenings fixing bugs in your bog-standard Rails app, it's much easier to persuade the guy that spends them fixing bugs in bleeding edge javascript frameworks than the guy that spends them with his wife and kids.