Other processors
Intel and AMD have a lot more legacy 32bit (and even 16bit) code hanging around, removing 32bit support would cause a lot of headaches. ARM chips are usually used in embedded devices which are typically designed together with the software they will run so there's far less problem.
There have already been pure 64bit chips with no 32bit mode, such as Alpha...
Interestingly while ARM64 is quite new, their primary competitor in the embedded space is MIPS, and MIPS64 has been around since the early 90s, but they failed to capitalise on their lead over ARM.
Biting the hand that feeds IT
