I'm not really sure where you're getting Turok from. Its an established franchise, that they've actually tried to make decent again. It'll make some money based solely on the name. You have to remember, that the game nerds are not the ones spending most of the money on games. Also, not all games start out crappy, they end up that way because of deadlines and other bureaucratic issues. By releasing any product they'll at least get some return on their investment. As for why do the developers themselves do it, well remember that people have to get experience somehow. Gaming has become a lot about the business side of things. I'd actually compare it more to car companies than movies or music. I mean, you have to earn the right to be able to work on designing and building a Viper or Veyron, you're probably going to have to do that with some crappy cars before you get that opportunity.