WSL may be fine for a Windows user to get some access to Linux, however for me it misses the vast majority of what I value in a desktop distribution -Better Window managers. This is subjective, but with Windows you are stuck with Microsoft implementation, and if you might like a tiling window manager, or Plasma workspaces better, well you need to run something other than Windows or OSX.

-Better networking. I can do all kinds of stuff with networking. Niche relative to most folks, but the Windows networking stack is awfully inflexible and frustrating after doing a lot of complex networking tasks in Linux

-More understanding and control over the "background" pieces. With Windows doing nothing a lot is happening and it's not really clear what is happening where. With Linux, it can be daunting like Windows, but the pieces can be inspected more easily and things are more obvious.

-Easier "repair". If Windows can't fix itself, then it's really hard to recover from a lot of scenarios. Generally speaking a Linux system has to be pretty far gone

-Easier license wrangling. Am I allowed to run another copy of Windows? Can I run a VM of it or does it have to be baremetal? Is it tied to the system I bought with it preloaded, or is it bound to my microsoft account? With most Linux distributions, this is a lot easier, the answer is "sure you can run it".

-Better package management. If I use flatpak, dnf, apt, zypper, or snap, I can pretty much find any software I want to run and by virtue of installing in that way, it also gets updated. Microsoft has added winget, which is a step in the right direction, but the default 'update' flow for a lazy user still ignores all winget content, and many applications ignore all that and push their own self-updater, which is maddening.

The biggest concern, like this thread has, is that WSL sets the tone for "ok, you have enough Linux to do what you need from the comfort of the 'obviously' better Microsoft ecosystem" and causes people to not consider actually trying it for real.