They aren't using it "the same way Debian and Ubuntu do." Debian is named Debian not "Debian OS." Ubuntu is named Ubuntu not "Ubuntu OS." The releases have own names.
Elementary "OS" guys use it like OSX and iOS which both conform to the real view: Note "OSX Lion" or just Lion and definitely not "Lion OS."
I suppose that you had better go down and sort out those blatant liars CentOS, ClearOS, OS/4 OpenLinux, SolusOS, PureOS, Chrome OS, Joli OS, Peppermint OS, ZevenOS and PCLinuxOS.
How dare they try to advertise themselves as operating systems.
Elementary "OS" guys use it like OSX and iOS which both conform to the real view: Note "OSX Lion" or just Lion and definitely not "Lion OS."
Clarity is important.