Most programs, games especially, can't easily use more then one or two cores effectively. Programming for multiple cores is very difficult and a large number of problems can arise from utilizing more then one core. Each core maintains their own state, so cores have a hard time working on the same problem. You can break problems up into multiple threads, but these threads can't easily communicate.

More cores create more heat, so you have to run more the cores at a slower clock speed. The result is much slower per-core performance. I called the FX processors a failure, because their attempt at making superior processors by adding many, slower cores clearly failed.

Intel had a similar example of a failed processor architecture with the Pentium 4. The plan was to create an architecture that could reach 10GHz. They quickly discovered that heat was a much larger problem then they had anticipated. It is a good thing that these companies are trying new things, even if some of them result in failure.