its not always fear of failure. Sometimes you have to pragmatic too. For instance, doing a startup in Bay area with a family is not practical for a lot of people, especially given the current rental/living expenses.
That's still fear of failure, only in that case, the fear may be well founded. If they fail, they cannot feed their family, so they are afraid of failing and probably for good reason.
The higher your financial obligations are, the more weight the ruin side of the equation holds.