MacOS isn't walled at all. I can install anything I want on it, no "permission" required. Plus it is a legitimate UNIX system (officially certified and everything), you can even install an X server on it. Notarizing your software is optional and trivially worked around by end users, while still being fairly effective malware protection.
Thank you for a comment that has nothing to do with the article and contributes nothing to the discussion. Go back to Reddit if you're going to do that.
Now iOS is a different story.