[crematoria]

Source? People write CLI tools in Ruby and Node.js these days, so I really doubt that anybody would use the term "systems language" to refer to languages well-suited to building CLI tools.

[IshKebab]

https://www.wired.com/2009/11/google-announces-a-new-program...

> As a systems language, Go is intended to be used for developer applications like, for example, web servers.

Couldn't find a citation for CLI tools, but that should satisfy you (since people write web servers in Ruby and Node.js too).