I disagree for a number of reasons: The slow performance would eventually have lead to Intel realizing its bad idea. They would use market share to competitors

I disagree for a number of reasons: The slow performance would eventually have lead to Intel realizing its bad idea. They would use market share to competitors on different ISA. Windows at some point would want to be on faster processors and would again run on some of the others. Windows doesn't have undying loyalty to Intel. Other people then AMD could do a x86 implementation with some 64 bit overlay as well. Transmeta style. That kind of system would beat Itanium as well if it was put on top of a fast RISC processor. And at some point AMD even on 32bit would massively gain market share as they invested more in faster RISC style processors. So Intel would have massive pressure from the bottom end and the top end. And in any possible future AMD at some point it gone do something with 64 bit. The idea that the whole industry goes massively backwards and stagnates for years because Intel monopoly doesn't really work in practice.