Huh? An operating system, as defined by Andrew Tanenbaum[0], the author of both Minix and of the best operating textbook ever, is a combination of:

- an "extended machine": provide usable abstractions over the hardware to reduce complexity to a manageable level

- a "resource manager": provide for an orderly and controlled allocation of the processors, memories, and I/O devices among all the various programs wanting them.

By that definition, Linux is very much an operating system... unless by "Linux" you meant the kernel only without the additional tooling (systemd, libc, coreutils, shell, etc.) that distros ship with.

[0] https://en.wikipedia.org/wiki/Andrew_S._Tanenbaum

This comment would impress a lot of people somewhere that's not HN.