Who are design systems for?
Open-source design systems aren't necessarily meant for public consumption.
"If a design system is by a company, then it's for the company. It might also be open source, but any ol' random developer who wants to use it isn't the target audience." - Chris Coyier
While you might open source your design system, and technically anyone can clone and use your system, that's not the intended use. Design systems are meant for internal consumption. We open source our design systems to share knowledge and best practices.