I'd like to question the implication that your life is not affected by work as a normal employee of a big company. Sure, it's most probably not going to be as intense as for a start-up, but that's less because of start-up vs big company, but much more about how committed you are to your work in general. I know lots of people working at big companies who have crazy work-hours and whose social life definitely gets affected by that.
Let's face it, if you want to be successful - start-up or not - you'll have to work your butt off.
I would go one further: Aiming for the top of the corporate ladder can have a bigger impact on your personal life than doing a startup. For example (from my own experience) I work more hours in my startup but the fact that I get to do it when and where I want it (in the middle of the night sometimes) makes it much less demanding than being away from your family because you're out of town.
Of course, it depends on the type of startup versus the type of business and your ambition level inside the business, but in my case the startup "feels" more relaxed than any business I've been in.
There are different different values of "successful."
Not everyone thinks that being successful means becoming an executive. Many people equate success to being able to pay their bills and have fun away from work. And in most cases, that doesn't mean working your butt off.
Let's face it, if you want to be successful - start-up or not - you'll have to work your butt off.