I think a comment below really hit it on the head: "If you spend the same amount of effort chasing paying customers, as you do chasing VCs, you'll be able to pay all your bills and then some with your revenue."

I know some folks who spend years of their life (and more than that, in terms of its physiological and nervous impact, probably) chasing funding. If they just bothered to make small sales and steadily grow revenues - ideally, bt not necessarily recurring - during this period, they wouldn't need funding. And if they wanted it, they could get it on infinitely better terms, not because the VCs really care about how cash flow-positive they are (it's the marketability potential that impacts the valuation on exit in an acquisition, not concrete P/L--that matters more in IPO, which is really not practical for the moment), but because they really are in the position of not actually needing it to survive.