In particular this means that this is anything but open source (at least if you go by the OSI definition, which I do).
Yeah, I was thinking the same thing. I know some pedants argue that OSI don't have a registered trademark on "Open Source" and that they "don't get to decide what is or isn't open source." But in practice, many (most?) of us do acknowledge the OSI definition as being the de-facto definition of "Open Source."