x86, ARM, etc. are huge ecosystems and things are orders of magnitudes more complex than we use those letters vs you use these letters for ISA. The answer for

x86, ARM, etc. are huge ecosystems and things are orders of magnitudes more complex than we use those letters vs you use these letters for ISA. The answer for your question can be: because somebody didn't put enough effort / attention to make it work Is it true? I dont know, but can be