"Linux" has become the general term used to refer to an OS made up from: Linux kernel + GNU tools/libs + lots of other really important components that never get recognition. Richard can call it "GNU" all he wants, but he's just making himself look silly. And given the increasing popularity of non-GNU libc versions and compilers his stance is only going to weaken.
I've never cared for the term "GNU/Linux" as it makes it sound like Linux is a GNU project. Anyway, the argument is moot as we'll all be calling it "Systemd OS" before too long.