You think startups are any different? Unless you are one of the very first employees in a startup that is massively successful, you're not going to benefit financially compared to a job at BigCorp. In fact, the loss of higher salary, bonuses and benefits mean that startup employees are often working longer and getting less in return.
It's time to get rid of the culture where you have to stay in the office as long as the founder does- his incentives are totally different. A 40 hour week sounds great to me, but it requires a cultural change, not a legal one.
Not everyone can be so lucky though- startups are often doing more interesting stuff than large companies, so there's an appeal.
If my employer demanded a tie and I didn't want to dress that fancy, then there's a disconnect between their expectations and mine. We don't fit together well. Some people will like working 50, 60, even 80 hours per week. Some won't. The people who should be employed there are the ones who like what that company has to offer them as the whole package.