The option to show the Backup and hidden files should not only be in the
preferences dialog, but in the Nautilus file manager window menu.

Reason:
As a user, I don't permanently enable the "Show Backup/Hidden files"
preference, because it clutters the file listings unnecessarily. However,
I'd like to sometimes check which temporary or hidden files are in the
currently selected directory.
Right now, I have to go to Edit->Settings, and enable the  option, then
look at the directory, then do the reverse. A better solution for this
not-so-uncommon option would be to just toggle it using "View->Hidden and
Backup files".

Originally, I wanted to file a bug that I would like to have separate
preferences for showing Backup files and Hidden files. But actually, a
simpler way of toggling the display would be more useful for my typical usage.