I don't follow why I'd sign something can cause legal issues for me if I
could do without that.
I think in the question the GNOME community vs foundation members are
mixed up. Those are not the same thing.
I'm a bit surprised that people see a Code of Conduct as something new.
See e.g. https://mail.gnome.org/; we already expect people to follow the
Code of Conduct.
And before someone misunderstands, I have enforced the Code of Conduct,
I've signed the existing one and agree to the thoughts behind both.
This maybe my annoyance with volunteering and then getting too much "do
this or else".. that takes the fun out of it. I prefer "assume people
mean well".