A lot of users still like the mix of a good UI for most tasks, while being able to do a lot of power user stuff without an added layer. Plus many will choose macOS also for the hardware, which support for new chipsets is still rather WIP under Linux.
> A lot of users still like the mix of a good UI for most tasks
This is funny; it's actually the main reason why I asked for a PC when I was up for renewal at work, so I can run Linux on it.
I truly like the hardware of the mbp, especially the screen (don't care about battery life, I mostly use it at a desk with power nearby). The OS itself is fine, since it can easily run most of the tools I use. I also like how it handles special characters (I can easily type French on an US-ANSI keyboard) to the point that I've implemented that on my Linux and Windows machines.
But what kills it for me is the UI behavior. The window management drives me crazy, especially when multiple screens are involved. And there are quite a few aggravating issues, like being unable to control the audio output of my screen's speakers (connected through DP), being unable to turn off external screens (sometimes I just want to use the power of my monitor, which has an integrated KVM).
Yeah, I know there are programs trying to fix these, but I have to go out of my way trying to find them, and then they're hit and miss. On Linux, everything works as expected (though, granted, it's possible I've won the hardware-compatibility lottery, since it actually works better than on Windows).