Not all packages which are forked from existing components are accepted by FESCO. Would you accept a older forked gcc or linux-lts kernel accepted in fedora just becoz someone is interested in maintaining it?
Gnome components are forked so much becoz there is an audience for older versions and people are actively using it. New versions of nautilus should have more functions on top of old features, but instead calling it as unmaintainable and removing the features is not what users want. Now instead of nautilus 3.6, people are willing to stay with nautilus 3.4 with new name 'nemo'. Within a couple of years if the gnome project continue the tradition of removing the core features and thrust some feautres that the devs think is important, I am pretty sure there will complete fork of all the components.