When the consumer buys a CD or other media device it is not fair to them that the product they bought is not useable by they to the full extent.
This is due to the problem that some companys have with copyrights, being violated. Some people abuse the rights that they have. This doesn't change the fact that makeing an extra copy of the CD is now illegal. This is only because people who make the CDs are missing out on a little bit of profit. The main problem with this is that they have started encoding their products so that you can't download the music or whatever to your computer to protect yourself from making backup copys.
This also disables the posibity of puting a leagaly purchased CD onto a mobile media device. Knowing the ability of the product would posibly decrease the sales of the product. Therefor they wont let you know what type of software they have on the CD's.
This is a link that presents some very definitive points on why we should limit the abilites of DRM