> Most common software that typical buyers use is available on Mac or Windows
That's not how most people think. Most non-techies are either fluent with "how to use a Mac" or "how to use Windows" and they will just stick with that inertia.
For a lot of people, learning a new OS is an ordeal.
Also possible that people have paid for licenses / apps and thus want to stay with the OS those will run on, instead of having to pay again (if it's even an option).
That's not how most people think. Most non-techies are either fluent with "how to use a Mac" or "how to use Windows" and they will just stick with that inertia.
For a lot of people, learning a new OS is an ordeal.