lol it's difficult to put Linux based OSes under one umbrella term and please everyone. And no calling it GNU/Linux isn't a solution. Linux-based OSes are by nature made of many bits and pieces, many independent projects duct taped together, and the GNU programs are only some of them, they can be even easily replaced.
In contrast, something like FreeBSD, for example, is one monolithic project which aims to be a whole operating system, I think, in theory, the Linux analog to "FreeBSD" would be the distros themselves, "Ubuntu", "Fedora", "Alpine Linux" etc. those are projects that strive to be complete operating systems, but then it's a hot topic to put them under one umbrella term apparently.
People are trying to draw a line between your traditional Linux distros and things like Android.. which.. well.. fair.. but... hmmmm...