The main reason imho is that they don't understand people, they think everyone is as smart as they are, and this results in trying to create a perfect product w

The main reason imho is that they don't understand people, they think everyone is as smart as they are, and this results in trying to create a perfect product which is impossible, and hence, they lose motivation to complete it. What smart people need to realize is that the rest of the people are not that smart. Proof? They buy virtual goods. Never assume people will not use your product, this is too big of an assumption. Let them decide because they don't think like you.