The reason is because the world is full of people who believe they have a billion dollar idea, and all they need is to "find an engineer to build it". By contrast, there is not a single engineer running around offering to pay $10,000 for a killer idea so they can use it to execute their way to a billion-dollar business.
Thats true, but there are also surely people executing on poorly thought through or uninspiring ideas since they've been told to not go through the various thought exercises one should go though before settling on an idea for a new venture.
If you lack the common sense to realize that in order to sell something people need to be willing to buy it, then all the startup wisdom in the world won't help you.
