They are not tied to apple, but it is often the preferred OS.
I haven't used MacOS/OSX in a couple years, but at least back then it was in my opinion by miles the best out of the box experience for audio related things.
E.g it took me hours on Windows 10 to have a basic setup with reliably low latency, without clicks, noises, dropouts and generally getting the OS out of my way (e.g. automatic rebooting for updates is kinda suboptimal if you plan to use your laptop for live music). Never had anywhere near the same level of issues on macs.
Sure you can make it work on Windows or Linux, but if this were my main job, I'd need very specific reasons or strong personal os preferences outside audio to not pick an Apple.
Movie composers are often Windows, not Mac. Even after the new MacPro It's much easier and cheaper to put together a monster PC with no-compromise specs for loading huge sample libraries and running huge mixes.
Also, these people have people to do tech support, setup, and configuration for them - often onsite - so mostly their systems "just work."
I haven't used MacOS/OSX in a couple years, but at least back then it was in my opinion by miles the best out of the box experience for audio related things.
E.g it took me hours on Windows 10 to have a basic setup with reliably low latency, without clicks, noises, dropouts and generally getting the OS out of my way (e.g. automatic rebooting for updates is kinda suboptimal if you plan to use your laptop for live music). Never had anywhere near the same level of issues on macs.
Sure you can make it work on Windows or Linux, but if this were my main job, I'd need very specific reasons or strong personal os preferences outside audio to not pick an Apple.