Any copying program has a certified legitimate use, in that it can be used to produce a working copy of software as allowed under US copyright laws (which incidentaly the DMCA prevents you from doing and is therefore an ilegal restriction of consumers rights). The targets they're after are file-sharing and cracking, although cracking is covered by the same rules as copying, if it is done to allow a backup to be made. But Unknown_K is spot on when he says that soon you won't buy, you'll rent/lease, and then you're screwed. It's already happening with M$ DRM which requires you to re-purchase the music if the key is changed.
Key's can be changed by the person who sold the music, by changing your harware, or by M$ (who's usually the one who sold it as well...) check out The Register
or The Inquirer
for full details of how you're losing your rights, and lots of sad tech news