That's the tip of the iceberg MS want everyone to see, and point the finger at.
MS want people to stop using Linux as an alternative since they lost the battle when they attempted to kill it during the Ballmer era. The plan now is more subtle: making sure everyone using Linux will want to do that from a Windows machine, with all the implications about security and privacy, which would be non existent since any malware (or Windows itself) that for example used Windows keyboard drivers to sniff passwords while one connects say to the bank under WSL "because it's more secure" would be 100% undetectable from that Linux.
The next step will be libraries to access Windows internals and GUI from WSL, so that one can build hybrids that run only on Windows+WSL; very convenient, but unfortunately now Linux is displaced and the only way to benefit from all that software will be to run it under Windows. In the end, MS will create their own Linux distro which runs on top of Windows and will essentially kill all other non-server oriented Linux distros.
Most see WSL as a good thing; I see an elaborate, and have to admit, very clever, way to take complete control of Linux in the next years.