Comment 12 for bug 344228

Hard links don't work across mount points. So if the user picks a wallpaper that does not reside in his/her home folder it may not work depending upon how their system was set up.

For example I had a system where most of my image/music data was on a separate mounted volume from my home directory. Hardlinks wouldn't work in this case. Symlinks would but then you're back to the loss of wallpaper on delete issue.