Great comment. But you don't have an ethical obligation to be heroic in your startup. You are obligated to be honest when the investor makes their decision to back you, you're obliged not to be negligent in your execution, and you're obliged not to misuse their funds. But your kids, as it were, come first.
If you took investment from friends and family under the auspices that it would probably get paid back, you lied to them. This is one reason you probably shouldn't ask for investments from friends & family.
Professional investors know the score. Even the very most promising startups bear an unacceptable risk of failure in isolation. They make sense as investments only as a group. Even then, many (most?) VC funds lose money. They exist because foundations and pension funds want to put money into VC as an asset class, not because anybody is counting on returns.
