Comment 7 for bug 221550

FWIW, it was our intention when founding Ubuntu to dodge the Linux vs. GNU/Linux controversy entirely. I remember an early discussion about whether we should be "Ubuntu Linux" or "Ubuntu GNU/Linux", and eventually we agreed that it was better just to be Ubuntu and not have to worry about it. Now, this went slightly awry when we couldn't get the ubuntu.org domain name and ended up with ubuntulinux.org for a while, but it's for that reason that we prefer ubuntu.com.

I rather suspect that "Ubuntu is a Linux-based operating system" is intentionally ambiguous.