Here is my issue.
I am playing Assassins Creed IV right now, and this game has TONS of collectibles. My OCD wants me to get as many as I can on that island, but then i start feeling anxiety because Im not doing anything to progress myself further along in the main story.
I feel like when there are so many collectibles, it detracts from the main game simply because they are using that as a way to extend the games lifespan rather than putting more focus into the main quest line.
Also, not having a clear cut reward at the end of the collecting also sucks. Its hard to get behind doing something so monotonous if you have no idea what you are doing it for.