Guess it's a matter of perspective and just how much one trust teachers to do the 'right things' when restoring (as well as the restore system).
Another, that I may have said in a forum but will repeat it here ... as far as I think, one cannot have enough backups ... backups of courses, data folder backups, mysql dumps, and full site backups. And best, if one could place copies of those backups outside of Moodle - they are humanly recognizable files in a 'regular' directory then. By 'outside of Moodle' ... another folder not within moodledata or moodle code folder. Better yet to rsync the 'alternative backup area' to other media or a true backup server.
The symlinks could show to the teacher IF admin were to setup a file system repository in their course. They can acquire files from them, but cannot upload to them.
We all get to choose how 'paranoid' we are and how much we are willing to do considering.
'spirit of sharing', Ken