Most geeks that I know aren't trying to build apps that make money, they're trying to build apps that are fun, and that their friends think are fun.
If you offered me two choices
A) Make a million dollars a year doing something you hate that nobody will know about or care about
B) Make no money doing something you love that your friends think is cool.
I will almost always choose B, and I think most hackers will also always choose B. I would go as far as saying that choosing B is one of the defining characteristics of a hacker.
I got into computers because it was fun, not because I saw dollar signs at the end of it. Writing a video sharing app is a lot more fun than writing a software that reduces credit card fraud.