The problem is that users and developers are not satisfied with the current form of Gnome or the way the project goes. You have now two forks of Nautilus - Nemo and Marlin and each come with the burden that both projects have to be maintained and tested/used by users and developers - with the result of lower developer output as if you have only one project. All this dissatisfaction lead to more forks and a lot of users/developers go somewhere else - which slow down development of the projects and the spread of Linux on the desktop which is the most bad thing in this case. Sorry to get OT of the Nautilus problem but we have too much forks:
KDE3 - Trinity
Gnome 2 - Mate
Gnome 3 - Cinnamon and somehow Unity
and the other DE's
so someone can only wounder how many developers and users switched projects/DE's. It's time to think about what developers and users want and later kill/end at least three of this projects.