Pretty sure most of you already know this but for those who don't: you have two clipboards in Linux.
One is the traditional clipboard where you copy with control c and paste with control v.
The other one is when you highlight text and use the mouse middle click to paste text.
Linux is the kernel, useless without actual programs to run on it. In general the minimal set of programs to make a Linux system actually useful (cd, ls, cat, ...) are provided by the coreutils package, a GNU project.
RMS, the founder of GNU, was pissed that people were using Linux + his software and simply calling it Linux, so he insisted that the proper generic name for "Linux" distributions was actually "GNU/Linux" (i.e. GNU utilities + Linux kernel).
OP's joke is that we name stuff without specifying their components or needed tools all the time, so we shouldn't bother doing it for Linux.
You vlassifying it as "pedantry" supports my point.
It's also ironic, considering you told somebody else to not call it GNU+Linux instead of the other way around.