Why do people not pick up drops?

Not to mention that, at least for me, the pet sometimes picks up nice stuff I never even saw drop.

Indeed, I've not been able to revive my pet for a while thx to the CS error, but judging from redoing the ToT quests, I would seriously miss a friggin pomegranateload of pieces of time and some occasional scrolls and equips. Also, though the NX to meso ratio is useful, for a guy with an ordered, slightly compulsive mind, cleaning the map is worth alot on its own, and that would be insane without a pet.