Making Apple USB SuperDrive work with other Apple Hardware
You can edit a plist file by following the instructions found here to enable it on your system, however be aware you won't be able to boot from it (such as installing an OS via CD/DVD at boot).

I have no idea why Apple place the limitations on things like this, other than the potential that it makes things difficult for people (such as myself) who want to stray from normal configurations by installing two hard drives rather than a hard drive and optical drive in their systems. By making it difficult for the masses, they create a more stable experience overall as they have more control over the default configurations.

It's a combination of the firmware on the device, and the plist file which tells the OS whether to recognise the device. There's something in the EFI which prevents it working at boot level though which I don't know enough about to provide further information on though.