Re: MS is between a rock and a hard place with desktop windows
This has nothing to do with the kernel and a lot to do with the amount of software that is compiled natively for x86 and the dearth of software compiled for any other architecture.
Microsoft have tried repeatedly to support other architectures. Even Windows NT had versions for Alpha and they've tried for PowerPC, Itanium and ARM too. The problem each time is customers say their software runs on x86 and Microsoft have produced sucky emulation layers which are either too slow or come with a bunch of restrictions.
The only time Microsoft have managed to pull off an architecture switch is from x86-32 to x64 and that's mainly because the processors were backwards compatible. So the Intel seeded the market with 64-bit capable processors and Microsoft were able to finally pull the rug on 32-bit. And the 32-bit software was able to run reasonably because the WOW32 layer in Windows is basically thunking stuff rather than full blown emulation. But it took a LONG time.