Coding to specific hardware will get such an app bounced from Google Play, in fact - which is why OEM-specific apps aren't found there. Mom has a ton of apps that are cross-compatible, and she has both an Android smartphone and an Android tablet - most of those SAME apps also work in BlueStacks and all her GAMES do. WP is still at 3%, and Android apps won't run without modification. Without that, I don't see how anything has changed.

At least with the desktop you could make a case (however questionable) that Microsoft has a big existing market. Then there's absolutely no reason to port them in the first place.

It's just not practical even if they could somehow convince Intel and AMD to dedicate significant time and effort into hand tuning the emulator for each and every one of their architectures. And that's running directly on Android without having to worry about the additional overhead of running Windows itself as well. and as we've seen with Google's own x86/ARM emulator, that's no easy job as it's close to 2.5x slower then Intel's emulator with far greater power consumption as well. Microsoft probably hasn't devoted anywhere close to the same amount of time on it and would be forced to write a single emulator that would cover all use cases on all available x86 hardware. Even then Intel's emulator doesn't have perfect compatibility. Intel knows their own processor architecture much better then Microsoft, and have undoubtedly have years of experience studying typical Android code though.

But Intel can write their own emulator specifically optimized for Android and the peculiarities of each and every individual processor they support on Android. That's what Intel does on Android to support apps that don't natively support x86, the performance hit is tangible but not huge.

Surely ARM commands can be emulated on x86 CPUs without a big performance hit (if any)?

Bluestacks android emulator arm intell