It makes sense from MS's perspective. They started not liking Linux, and now have integrated it in their OS with WSL, thusly becoming a full clown for the great hypocrisy compared to their original dislike of Linux.
I live in Linux; what I do not know is Windows. Don't have any, and haven't had to touch it in over a decade. Should I know WSL if I expect to never have to use Windows for the rest of my life?
nope. it's just a fancy word for a linux VM running on windows with special integrations like full file system access etc.
it's mainly used by developers who need to use windows for work but want a linux filesystem and command line for development. integrates well eith VSCode.
15 years ago, it was hard to be a developer and avoid some contact with Windows (unless you were senior enough to have some pull), especially in the East Coast, where all high tech lags by about 5 years. Now days, the assumption that everyone must have to have some Windows interaction is more of an ass-U-me.
There's exactly one Windows machine in my life right now, and it's my wife's work computer. I only have to touch it when it's fucking something basic up, like audio, and I couldn't install something like WSL on it in any case.