I am not going to dispute your claims, MacOS does not run on non-Apple hardware.
What I am saying is that many people that would have been Linux users are now MacOS users. And one of those people is me.
I was a hardcore Ubuntu / Debian fan, but then got a MacBook Pro from the company I worked for in 2014. After moaning about it for a while, I'm now a convert. Initially it was because of the hardware, as I love Retina displays for example.
My younger self wouldn't believe what I'm about to say, but things break a lot on the Linux desktop and I don't have the patience for that kind of crap anymore. Not sure how it is nowadays, but back when I was using it, the presence of an Nvidia graphics card meant any upgrade could break your setup. Which isn't acceptable given Nvidia's popularity.
Many times it isn't Linux's fault of course. Surely you can't blame Linux for Skype not working, but the general availability and quality of apps is a big problem. Also I agree that you can't expect Linux to work flawlessly on all laptops and some research is needed for a good experience. Thinkpads are in general good and some Dell models too. But this information is scattered all over the place and translates in even more time lost.
Go to any conference and you'll see a majority of people with MacBooks.
Those people could have been Linux users instead. They were Linux users only a few years back.
I'm not saying that I'll never use Linux anymore. I keep using it on the server-side and I might be back to a Linux laptop someday, due to Apple's newfound hostility to power users.
But just an FYI, the freedom argument doesn't really win me over. If all other things are equal, I prefer the open source solution of course, but I've got work to do, bills to pay, projects to finish and a family to take care of, so until Linux improves to the point where I can do those things without wasting time, I'll stay on MacOS.