To be fair it's quite impressive WSL1 got this far, but ultimately it was doomed from the start if one targets perfect compatibility.
Given there's no "Linux specification" the spec is the actual code, nooks and crannies and all, down to nitty gritty details and implicit behaviours that end up indirectly getting relied upon. The only solution is to basically implement these in excruciating details, which may or may not possible depending on the Windows things being wrapped. Then the question of intellectual property, copyright, and licensing come in, as MS would have to ensure that it's a clean room implementation or be subject to GPL terms (cue the Oracle Java vs Android shenanigans).
So at some point it makes sense to just throw a VM at the job, cleanly separating realms, sidestepping any legal landmines, and ensuring perfect compatibility, especially as the whole HyperV infrastructure is quite solid and used throughout the MS ecosystem as a general strategy, e.g the Xbox uses HyperV to isolate games and apps.
Tangent: I wish (the VM part of) WSL2 would be available on Xbox, allowing one to run Linux while keeping the whole regular OS and features!
Given there's no "Linux specification" the spec is the actual code, nooks and crannies and all, down to nitty gritty details and implicit behaviours that end up indirectly getting relied upon. The only solution is to basically implement these in excruciating details, which may or may not possible depending on the Windows things being wrapped. Then the question of intellectual property, copyright, and licensing come in, as MS would have to ensure that it's a clean room implementation or be subject to GPL terms (cue the Oracle Java vs Android shenanigans).
So at some point it makes sense to just throw a VM at the job, cleanly separating realms, sidestepping any legal landmines, and ensuring perfect compatibility, especially as the whole HyperV infrastructure is quite solid and used throughout the MS ecosystem as a general strategy, e.g the Xbox uses HyperV to isolate games and apps.
Tangent: I wish (the VM part of) WSL2 would be available on Xbox, allowing one to run Linux while keeping the whole regular OS and features!