Quite the contrary, macOS has been a boost to Unix. You are rather naive idf you think all macOS users are potential Linux users. macOS helped make Unix a strong competitor to Windows. It helped demonstrate that a Unix system CAN be user friendly something many people used to think was impossible.

Thanks to the rise of macOS windows has become a second class citizen for many development tools.

The non-gui layer of macOS and Linux can for the most part easily be shared. It means open source developers of non-gui tools have a much bigger usergroup and potential contributors.