WSL has many issues which are not getting fixed, and rather classified as "won't fix, as out of scope". Further, WSL isn't supported on Windows Server, which is really annoying if you're dealing with M$ only infrastructure at your company and hoping to use WSL as an alternative way of deployment.

It's basically just a "cheapish" way of keeping Devs on Windows, preemting any semblance of competition by Linux desktop environments from forming. They know they lost the server market, but they can cling on to the Desktop environment market as much as possible, at the same time eating into apple's market share in this specific power user market. Not that Apple cares that much anyway, they're content with selling iPhones.