At nearly 11GB, downloading Cubase can take a lot of time, even though the application itself only weighs in at a couple of hundred MBs.
Because of the eLicenser, it is pretty fast to set the license up on any PC, and with a slimmer download it would be possible to get Cubase on another PC or newly installed PC more quickly too. In general, not all users even want this content (me included) so it’s basically just a waste of time and bandwidth.
Offering a minimal installer of about 500MB would be a solution to this. Groove Agent SE could still be included for example so no functionality is lost, but not with the content packs.