amuffin :
Because amd fails at cpu architecture.
Let's see...
AMD spends about $1.8 billion on R&D. This includes CPU, GPU and chipset development.
Intel spends about $6.5 billion a year on R&D. This includes a broad range of products, but a large portion is earmarked towards processor development.
The Core architecture is a very mature product. The current SB processors are the second generation of the Core iX series, and represent the fourth generation of the Core series (Core, Core2Duo & Core2Quad, Core iX 1156 & 1366, Core iX 1155). Intel has sunk a LOT of their R&D budget into these processors and has leveraged a good deal of performance out of this investment.
Bulldozer is the first processor in its line. It has not had nearly enough time to mature. That it has come out the gate at the level of performance it commands speaks volumes to its design team. Sure, it ain't no SB, but this team has built an entirely new architecture that is at least keeping in the same heat as SB, and on a fraction of the budget. As the architecture matures and we start to see corrections and enhancements to the design, we will see improved performance and efficiency. Will it ever be better than SB? Probably not. But it's still an accomplishment, especially when no one else is even trying to step up to the plate to compete with Intel.
AMD has always seemed to perform like this. The first generation of a new processor line always seems to suffer, but it improves as the R&D team takes time to perfect the architecture and add enhancements. The original Phenom was most decidedly a bomb, but the Phenom II is most decidedly a very strong performer.
Hopefully, given time, BD will mature into a very good product, just like the Phenom. At the same time, Intel will be moving forward with Ivy Bridge and beyond. I don't see AMD ever taking the performance crown again, but I do see paradigm shifts happening in the demand for general purpose CPUs. As we see more and more people using mart phones and tablets in lieu of laptops and PCs, and more consoles playing games, you will see demand for low-power, high performance processors, where other non-X86 architectures dominate the landscape.