How long until vendors start shipping "linux" software binaries that depend on a microsoft-specific quirk in their Linux kernel ABI reimplementation, and real Linux will need to add support for MS-Linux kernel ABI variant :)
Also, I imagine that if anyone ever tried submitting a kernel patch to support a Microsoft-specific ABI, Linus would rip their heart out Temple of Doom-style.
More likely I think is open source developers being asked to add patches to support limitations of WSL.
Not the worst thing in the world.
If they are a vendor starting from Linux, they'd not do this while adding support for WSL.
If they are a vendor starting from Windows, WSL is not an interesting target for them, and their customers wouldn't buy the product to run it on WSL – they'd have to name an actual Linux as the target platform, and it'd have to work there. It could happen with very dysfunctional companies, but I don't see it developing enough pressure to change anything about Linux.
How many people do you know with PostgreSQL or MySQL in production, on Windows? Or with those vertical solutions usually available only on Windows?
Emphasis on GNU.
This is usually where someone naively says "but GNU tools aren't that good and aren't used these days" (which is utter bs)
If you take the GNU and the linux out of GNU+linux and put it top of windows, what do you have left? Basically just windows. To hell with that. Windows is malware.
* Swift runs natively on Ubuntu, however on WSL only the compiler works. If you try to run the REPL it will crash.
* Emacs, slow start, seems to work for simple editing. Crashes when you try to install a package or when you try to list the available packages.
So there certainly are some bugs.