This smacks of the typical Apple, "you're holding it wrong" condescension. I understand why MacOS does things the way it does most of the time. That doesn't mean that I can't still find it frustrating.
As a Windows user, I'd be pretty concerned about the multiplatform story here. They say that this is MacOS only for now but they intend to eventually ship a Windows App, Linux App and web app.
It just sounds like a recipe for a Sketch situation where it's really just a Mac app and web (and other platforms) is a second class citizen.
You and the author are conflating two different kinds of "openness". The user is talking about the openness of the default visibility where you're presumably referring to the openness of the implementation.