If I'm not mistaken, you're talking about distributions. When I write 'operating system', I'm referring to a collection of programs that provide a set of utility for a user, such as file manipulation, the ability to compile other programs, etc. Distributions expand on that functionality by configuring everything, providing other programs, and methods to install more. But they mostly build off a common framework, the operating system. Linux is a component of that system that provides the framework. Should it get all the credit for doing so? Personally, I don't think so.