You can't — obviously. And folk like Amy Hoy @patio11 freely admit that.

The key word there though is "requires". I've encountered lots of companies that have spent silly amounts of money, often their investors money, because they've missed opportunities to validate their business model in cheaper ways. Either because they don't know how or they don't want to. Folk who are so focussed on the vision that their aiming for that they fail to look down as they walk over a cliff.

To stereotype slightly I'd say that folk with a dev background are more likely to go that route than not — since the business / marketing / user research end of the skill spectrum that can help with that stuff is less familiar to them.

Nothing against VC funding, and it's absolutely necessary for some companies. It's just that the majority of folk that I see trying for it are doing so before it is actually required. Either because they're missing ways they can continue more economically because they lack the skills, or they hope that the (lack of) positive feedback that they're getting so far will be solved by money.