I think that I can illustrate it best with a real example...
3DS Max creates some kind of "*.log" file into your C:/ directory (or anywhere you want), ok, it's created each time you open and then close 3DS Max, I don't want that file and I always delete it manually so I would like that CCleaner deletes it for me automatically... ok... CCleaner 1.24.180 does that... but only one time, then the reference to the file in "Custom Files and Folder to Clean" list disappear, so I think that is useless... CCleaner should keep the file reference and check each time if file exists and deleted it.