It is definitely a carrot dangle trick used to keep people playing longer, and thinking they have so much content, yet more than half (and I would wager 3/4-7/8) of the shit they unlock, they never will use. Just things in the way, making you feel successful, trying to get to the unlock you want.
If the core game brings you a fantastic experience, you are having fun, then what the fuck is the issue?
Maybe I have been gaming so long that I appreciate things like this more. I grew up on freaking Pong/Space Invaders/SMB. All those "content rich" experiences.
Hell, trophies and achievements have not even been around that long, and people complain with smaller games with no Platinum's. The hoarder/collector syndrome is real. I just wonder where in our human evolution, the first humanoid to take more shiny stones from another, and say, MINE! I need more than the others!