Because this has deep integration with potentially sensitive data?

Then don’t use it lol, they are under no obligation to share their code for someone else to steal

bad take. there is no point in posting it if we don't know if its safe to use. The world doesn't work on the "Trust me bro principle."

Okay fair enough. But as a developer it grinds my gears when I work hard on something and like a moth to flame I get asked to open source it (so others can copy my hard work)

It was a question. And the read me has a contributing section, so it's pretty logical to assume so. It is also incredibly niche as author says themselves; usually that means the more the better.