Its not really the actual limit. Nobody is writing architecture-specific code anymore. Being able to binary translate x86 won't change the fact that the program you are trying to run is trying to invoke a thousand libraries for a proprietary OS that will never open up or otherwise become portable, that is also compiled against a system call interface specific to only that proprietary non-standard OS.

If Windows on ARM allowed generic binaries, almost everything in the Windows ecosystem would be on ARM. For Windows.