Ok. flame wars, I don't care. But, using GNU/Linux and then pointing to only the GNU's view of the matter is very partial.
Consider the fact that if you're talking to normal users, you're looking at a desktop system, which typically means Xorg, KDE, Mozilla etc. So I wouldn't use GNU/Linux there, because that is NOT a GNU operating system. Its a Free and Open Source operating system, which is NOT equivalent to only GNU. That's rubbish.
I have a better solution. Avoid this war entirely and simply use the words "A Linux based Distribution". It could apply to "A FreeBSD based Distribution" too.