Ex: Successful founders do startups to solve problem and not more getting rich. How about Steve jobs, gates, Google guys etc, did they really startup only thinking about the problem to solve?
The outcome of building a successful startup is wealth, which can be nice, but that is rarely the only goal. Speaking for myself, the uncertainty, stress, craftsmanship, <i>perceived</i> control, problem solving and creativity all make it very interesting. It is a proxy for adventure as much as it is a way to get rich. I would probably not do startups if I cared about wealth, or wealth exclusively. Wealth seems like a good byproduct if you do something useful. Few people do startups exclusively because the problem at hand compels them to. Perhaps that answers your question.