You may not personally launch Xfce Terminal either but it doesn't mean Qubes doesn't use it as a terminal emulator. Qubes uses Whonix for anonymous VMs. It's bizarre that you're so set on making this distinction that not even the creators attempt to make.
Oh? Can you provide context where they say that Qubes uses Whonix? Under their doc file for Whonix they just mention that, if you want to use Tor, Qubes can make use of Whonix as a ProxyVM. That is the correct usage of the term "use". But not only is that not the same thing as using Whonix for a general backend for operation, many users forgo installing Whonix altogether.
This whole thing devolved from me just trying to make a distinction for other HN users so that they wouldn't get the wrong idea and not try out Qubes because they might think the systems are coupled and are worried of, say, being hacked by the FBI and put on more lists for using Tor.
