Gaming is going through what flying went through. The golden age of flight was fueled by near unlimited funding for any manner of crazed idea. You could come up with a nutty idea and somebody was willing to fund it (usual Howard Hughes). It isn't that way anymore. Producing airplanes became vastly more expensive and we went through tough economic times. The industry became more focused. Companies invested in purposed R&D to achieve a desired end. In all coming up with new innovative aircraft became costly. That didn't stop big companies like Boeing from coming up with some pretty creative and innovative ideas and enacting them. The games industry is going through a similar situation. This is why we see a lot of sequels. They are improving a tried and tested idea. Companies aren't going to want to invest a lot of money in a crazy idea with the cost of making a high end game so high.