I've met founders like this, recently. They're building some sort of social app that does something no one needs and no one would pay for. Maybe I'm being dense and they're actually geniuses, but I don't think so. Most startups fail, and I think a lot of that is because a lot of startups are really stupid. They're "solving" worthless non-problems because the founders aren't doing the hard work of finding real, valuable problems to solve.
Building a great product is really hard. And it can't all be done completely lean - at some point, you need to envision something so profound that people don't realize how much they need it. You don't just write Hello World, charge a buck, growth hack, and brag about how you got two bucks for it the next week. As Henry Ford said, if he'd asked customers what they wanted, they'd have said faster horses. Don't build a faster horse. You won't be great that way.