It could be considered cheating and is probably far more technically challenging than we would assume, but I feel like 10-20 hand-crafted "levels" that were dropped onto various planets in a "narrative" order as the player discovered them would have been a really good solution to give the game some sense of drive or meaning. As it is, the exploration is basically just for exploration's sake, and gets dry fast.
On a similar vein what they could do is implement buildings or something that are more unique and maybe have something special attached that the program is only allowed to generate so many times (you do have to give people a chance of seeing it so it has to be often enough that there is a chance to see it). And maybe some other features. Stuff that maybe gives you rare (only get at that building) blueprints or even an exclusive to that building ship.
Problem is, how much do you limit it to give people a chance of finding it but not make it seem not that rare?