Nothing about using Linux implies the rest of the system is open-source, or even particularly customizable. Look at all the pseudo-embedded systems (routers, NA

Nothing about using Linux implies the rest of the system is open-source, or even particularly customizable. Look at all the pseudo-embedded systems (routers, NAS appliances, TVs) that run Linux beneath a completely closed-source userland. There's a small population of hobbyists who build open-source platforms that use Linux as a component, but those have their own names (Debian, Gentoo) and there's no reason to go around intentionally confusing the layers.