> In 2003, AMD launched their 64-bit, but Pentium-compatible, Opteron CPU. Everyone stopped buying Intel CPUs for a while. Within a few years Intel made their own 64-bit, but AMD-compatible, CPUs to avoid entirely losing the desktop and small server market. They were right earlier: almost everyone immediately embraced AMD's instruction set and no one but HP wanted anything to do with Itanium.

This is the only reason why Itanium failed.

Had AMD not been allowed to produce Intel-compatible CPUs, everyone would eventually be forced to eat Itanium regardless how they tasted.

One doesn't get to be picky when food supply dries out.