Is it bad to support non-free systems? I do not think so. Users need to make
a transition from proprietary to free. I'd rather not see the creation of an
apparently impermeable border between the 100%-free GNU/Linux systems and the
rest of them. Do you complain that https://www.gnu.org/software/emacs/
(Emacs' main page) mentions Mac OS X, Windows and Solaris?
As for the distribution names not mentioning GNU, they actually are the names
chosen by the projects themselves. I certainly do not approve those choices
but is it a reason to change them? Maybe...
I would prefer the name ThinkGNU to ThinkPenguin. Anyway "ThinkPenguin" is no
"ThinkLinux". And I do not think the name matters more than the speech and
the actions.