Reason one is because Linux is GPL'd, Microsoft can't extend Linux without giving its extensions back to the community.
Reason two is because Linux is already established in multiple realms, so Microsoft can't bully its way into dominance. Microsoft has a respectable presence in server rooms, but it isn't absolutely dominant by a long shot. Microsoft probably has something going on in the embedded/hobbyist SBC space, but there's no path for them to dominate there. And, FWIW, Linux owns the supercomputer world. I also can't see IBM falling over itself to put Windows on mainframes.
Microsoft doesn't want to be Microsoft anymore; it wants to be Oracle and IBM and primarily make money off of business consulting and the cloud.
I think Windows will eventually become a presentation and slowly-phased-out compatibility layer on top of Linux, similar to the way macOS became Unix, but even less different than its underlying OS.
However, it should be noted that I'm not very good at predicting things.
Wine is 26 years old.
Depends on what you mean by "good enough". Wine is an incredible project that has achieved amazing successes, but it still falls short in a lot of ways.
I personally don't use Wine but I've encountered people online in the last 10+ years that use the argument that it's "good enough" for people to fully switch to Linux. Realistically, I don't think Wine actually convinced more than a handful of users to abandon Windows
I think this is unlikely. In many ways the NT kernel is superior to the Linux kernel. I just wish it were open source and didn't have the rest of windows around it.
The Linux kernel is ubiquitous and free-as-in-beer, so it might win out. Android has already shown how you can build a proprietary userland on top of it.
Good point.
WSL1 was a proprietary reimplementation of the Linux system call ABI as an NT subsystem. WSL2 is actual Linux running in a VM. That seems to be moving in exactly the opposite direction.