Dvd player manufacturers and software player creators have to pay a royalty for the decryption keys. Part of the reason you can’t just “copy” a protected disk is the copy protection itself, bad/false sectors, hidden data, subchannels, etc, to know how to read the disk you need a “key” which is what you pay the royalty for. Programs like the Windows copy command cannot read the disk correctly because it doesn’t have the “key”. I’m not 100% sure, but I doubt companies like Slysoft or DVDFab are paying these royalties and are using the argument of “fair use” to avoid legal difficulties (although they may be or have been involved in court cases). They provide a way of removing the encryption from the source material allowing you to make a copy which is not encrypted. The whole cat and mouse game of “fair use” and copyrighted material goes back to the Sony Betamax Supreme Court case. Google it if you want the details. This is just my two cents.