As far as I know.. this happens because in the Nemo's source code when you click in "Change Desktop Background" execute the cinnamon-settings.
You can try to edit the source code to call the gnome-control-center instead cinnamon-setting.
NOTE: In this example I'm running Ubuntu 13.04 with Cinnamon Desktop & nemo 1.8.4 installed from the ppa:gwendal-lebihan-dev/cinnamon-stable ppa.
Download the Source Code, Edit & compile.
1) Edit the gwendal-lebihan-dev-cinnamon-stable-raring.list file to allow download the source code.
sudo nano /etc/apt/sources.list.d/gwendal-lebihan-dev-cinnamon-stable-raring.list
Remove the "#" character.
# deb-src http://ppa.launchpad.net/gwendal-lebihan-dev/cinnamon-stable/ubuntu raring main
deb-src http://ppa.launchpad.net/gwendal-lebihan-dev/cinnamon-stable/ubuntu raring main
Save the changes in nano with Ctrl+O, Enter then Ctrl+X.
2) Open a Terminal and install the necessary packages.
sudo apt-get install build-essential
3) Install build dependencies.
sudo apt-get build-dep nemo
4) Create a folder to download the source code.
5) Download the source code.
6) Edit the file "nemo-desktop-icon-view.c"
Search for the lines 665 & 667 to change them.
Edit as per comment to remove "Add Desklets" action.
7) Edit the file "nemo-desktop-icon-view-ui.xml" to remove "Add Desklets" action.
Search for the line number "12" to delete it.
You can remove it with your favorite editor or with this command:
sed -i '/Desklets/d' ~/Downloads/src/nemo-1.8.4-20130709192207/src/nemo-desktop-icon-view-ui.xml
8) Go to the "nemo-1.8.4-20130709192207" folder to build the deb packages.
dpkg-buildpackage -rfakeroot -uc -b
9) Now you can install the deb packages.
10) Enable the "gnome-control-center-unity-appearance.desktop" file to appears in the gnome-control-center.
sudo sed -i.bak 's/OnlyShowIn=Unity;/OnlyShowIn=Unity;GNOME;/g' /usr/share/applications/gnome-control-center-unity-appearance.desktop
11) Hide the "gnome-background-panel.desktop" file from the gnome-control-center.
To avoid this:
sudo sed -i.bak 's/OnlyShowIn=GNOME;/NotShowIn=GNOME;/g' /usr/share/applications/gnome-background-panel.desktop
NOTE: with the "sed -i.bak" command, backups files will be created with the extension .bak
12) Finally you can logout and Login to see the changes.
As you can see the menu does not have the "Add Desklets" action and the "Change Desktop Background" will open the gnome-control-center appearance
Hope it helps.