[bcrl]

It makes perfect sense. Intel's strategy at the time was to hold back x86 by limiting it to 32 bits while pushing ia64 as the up and coming solution for systems with more memory. AMD then stepped in and designed x86-64 as a way to migrate from 32 bit x86 to a 64 bit platform while maintaining backwards compatibility with 32 bit applications. The first generation Itanium plonked an obsolete and slow Pentium II or III core (my memory is vague on exactly which core it was, but it was out of date by the time Itanium began shipping in production as x86 was evolving quite quickly at the time) which consumed large amounts of die space while not providing any performance benefit. As history demonstrated, AMD's strategy resulted in better performance for both 32 bit and 64 bit code while fitting into a larger share of the market than Itanium ever managed to take. x86 grew up while ia64 failed to grow down.

Low end CPU architectures like x86 and ARM have had great success growing up into the higher end of the market. Architectures attempting to do the reverse have not done so well. POWER tried to grow down into the desktop market as PowerPC, but lost out to the performance race of Intel and AMD pushing each other along in the x86 market. MIPS had a brief run while it was popular in embedded, but everyone has essentially moved on to ARM these days. There are way more ARM cores in the world today than x86 thanks to affordable and generous licensing terms.

It remains to be seen if RISC-V will do as well, and the association with Intel is probably not a good thing. Intel killed StrongARM. Atom was garbage, as the larger x86 cores did a better job of growing down into the power constrained space that Atom was targeting. It's hard for Intel to do anything but put their A grade CPU design teams on x86, and as a result any non-x86 CPU made by Intel will be inferior to the designs the x86 golden goose gets. RISC-V might have a few good years at Intel, but I expect it to languish and die like every other non-x86 CPU Intel has ever produced.