This /. submission reminded me of something I've always thought about: Ideas are cheap. Making them work is hard. Everyone I know has loads of ideas, some of them are incredibly good, and many of them coincide with ideas that other people have had. The fact of the matter is human beings are good at thinking up stuff. We're not all so good at making stuff happen. For instance, I, and loads of others have thought that a call screening feature on Nokia S40 phones (like on their older ones) would be great, but even given the source, very few of us would be able to make it happen.
Also, when I was young I read this book by Anatoly Markusha called Miracles on Wheels. He starts the book by relating stories of how little boys in the Soviet Union (inspired by the then-ongoing Space Race) would think up all sorts of ideas of how to go to space, without any knowledge of the Physics that actually makes those ideas work. Saying "Spacecraft should be like planes that abandon their wings and use a rocket engine at a certain height" is much much easier than actually describing a version incorporating that idea that will actually work.