Why make a game?

I've been thinking more about Nobles of late and trying to answer the question, "Why am I making this game?" I could be spending my time making adventures and scenarios instead. I could be spending my time finding more players. So why make a game?

The first thing to say is that I have no intention of making money from this game. I'm toying with the idea of just giving it away as a free PDF, or perhaps as a low-cost PDF through IPR. Nobles is not (at the moment) a game of quality equal to something like Spirit of the Century, or Dogs in the Vineyard. I don't expect that it will ever get to be that good, because that's not why I'm doing it. Also, I quite like my current employment and don't really want to invest the time to promote my game and change careers to Game Designer.

Secondly, I'm designing this game to better understand how games work. I thought about trawling the Forge and reading all the threads on game theory and game design, but I would much rather learn this by doing. I want to try and design a game that includes various features, that does the thing I want it to do. By making a game, I get to learn it the hard way, but I will learn it the complete way. The end result should be better games for my players.

Ultimately, I don't expect to become a game designer (although the story of how Kill Puppies for Satan led to Dogs in the Vineyard plays with my mind a bit), but I want to become a better GM. Making a game is part of my plan. As Judd Karlman would say, this is hitting the heavy bag.