I take it you don't perform backups all that often? There aren't that many reasonably fast methods to back up the huge hard drives common today. Tape is relatively simple, but also relatively slow, and expensive. CDR is very cheap and relatively quick with a fast burner, and burners are becoming more common than standard CDROM drives in new PCs.
It may take a lot of CDR's, but at least you've got the ghosted image, and it's only meant to be done occasionally to provide an image (in this case) so that you can fall back to it in case you screw up your system, or to allow an image transfer. It's not horrid for backups either, if you do mainly incremental backups rather than full backups, once you've done the first one.
Ghost of course can also simply transfer the image to another drive directly, I believe, rather than writing an image file, so you can make the first copy, and I believe the point was that the version of Ghost mentioned gives you the ability to perform a type of backup to CDR as well.