Itanium is far from crappy,
True, but...
it's a much better architecture than x86 for transaction processing.
...false. You cite ERP as an example but that is exactly what Itanium is not special at. For business apps and database apps, Itanium is not really any more exciting than Sparc or POWER (and is not as good as POWER). For that matter, it's not any more exciting than x86.
Itanium has lots of 64-bit registers, so if you're doing engineering, science, chess computers, etc. and write Itanium assembler (or have a good compiler), Itanium rocks. But for business apps like ERP, CRM, general databases, etc., Itanium is nothing special. It's not bad or awful - indeed, it's a good fast chip. But so is SPARC, POWER, x86-64, etc.
If you were a medium sized company that spent $10 million on a custom ERP, why would you spend another $10 million every few years to do it all over again? Then you get to train everyone and work through the kinks and bugs again... Most companies just want to use what works.
If your company's ERP is so custom that it only runs on Itanium, you're doing something very wrong. Most people's ERP is built is on some platform that runs considerably higher up the stack.