I think you underestimate the number of developer type people who buy Apple laptops because of the great hardware (M1, screen, battery life, touchpad etc) and are comfortable with MacOS, but they are not Mac developers and would also be comfortable using Linux or Windows if every part of the laptop works well with it.

Especially Linux, because they already use Linux on their servers and CI/CD, and some dev tools like Docker or anything filesystem-heavy run faster on Linux than MacOS even on the same hardware.