Heh, good comment about Notch, and the others you mention too.
For those who don't know, from the Wikipedia article about Notch - http://en.wikipedia.org/wiki/Markus_Persson :
"He is planning to stop working on this game after a recent deal with Microsoft to sell Minecraft for 2.5 billion dollars."
A huge outlier, of course, but the potential exists.
Sure. Lots of people are making money from desktop apps. Just because it's not hip or cool these days doesn't mean it's useless.