The previous poster was referring to code and module contributions to the GNOME project itself, not the sprucing up of the GNOME experience in Ubuntu.

GTK+, the underlying toolkit for GNOME, was substantially written and still substantially maintained by developers employed by Red Hat. If those resources had not been committed to GTK+ and GNOME, Ubuntu simply would not exist.

There's a difference between what you might regard as important, and the fundamentals of who contributes to an open source project. :-)