definitely, bottom line is that there still are bills to be paid. some sort of passive income is essential if one is to run a startup full time.
not to say I'm pessimistic or what, but my idea is that when people go into a business, they must go in with the mindset of being prepared to lose whatever money they have sunk in, instead of dreaming big from the get go. always unforeseen bottlenecks and stuff especially when one is new in the biz.