I still don't see the purpose of WSL
and I would really appreciate if someone could come up with a serious use case.
First to begin with, Windows shops are not interested in Linux. That's a fact. In all the places I've worked in the past 20 years, Linux was only used by few diehard fans, always looked upon with suspicion by the rest of the organization. If that army of Windows users would have had the slightest interest in Linux, a VM would have been a good start but speaking to any manager would trigger a reply varying from "no time for that" to "we're a Windows shop so we accept only Windows based solutions". I don't see how WSL would change this and what purpose could serve.
Then there is the development workstations. I might be wrong and I would appreciate to be corrected but even to this day there is no commercial software vendor for Linux desktop applications. Perhaps I'm not looking in the right direction but I can't find a market for Linux desktop applications. So all we're left with is server side applications that are developed for Linux which means no GUI needed since application will be accessed via the Internet browser running on Windows machines. The development of these applications has always been done and can still be done on a Windows/Mac machine, source pushed to a CVS repository/GitHub and pulled on the server with no difficulty.
So why is Microsoft insisting and Canonical/others happily obliging into this endeavor ? This is not going to increase the use of Linux. I don't see Windows regular users fiddling with their WSL to discover Linux and even if they would do it, Office will never run on Linux desktop and there will be no exclusive Linux desktop application so their interest will stop just right there. As it has been the situation for the past decades.
So who really benefits from this and what would be that benefit ?