Why? With the NT now you can run Windows binaries AND Linux binaries. With the Linux kernel you can only run Linux binaries (no WINE does not count). How is that an improvement?
In any case, the WSL experience on windows is still pretty sub-par. Until you can at least support the functionality offered by PodMan directly, including SystemD etc, it's not there yet. Even then, it's been kind of nasty to work with in general the handful of times I've tried.
Currently using Docker for Windows, and the msys bash that comes with Git, which though annoying for some things is still better experience wise than WSL is. Next desktop (Zen 2) will be on Linux.
Constantly people are bringing up that MS should switch to the Linux kernel. It makes zero sense.
You lose the ABI to run all the old Windows binaries out there when you can keep that AND run Linux binaries.
Also people seem to forget that the NT kernel runs on multiple platforms, on my XBox One with x86-64 CPU I can run old XBox 360 RISC CPU games. Windows 10 can run x86 binaries on ARM CPU:s. How is switching to a Linux kernel ever going to help with that?
Consequence of that argument is that Microsoft needs to support TWO flavors of Windows, one with the NT kernel & one with the Linux kernel. On top of that you get all the editions as a multiplier.
I did also like the Ubuntu UX a lot as well, not as much as Windows. Mac's is really usable but the MacOS-like shells are not quite there for the most part, at least from those I've tried.
Edit: NT kernel & hypervisor.