As the title states above, it's been announced that Rob (Chris Traeger) and Rashida (Ann Perkins) are leaving Parks and Recreation in the middle of season six, reportedly with "a big bang." (DON'T SHOOT THEM!!) These guys are great additions to the cast, so why the heave-ho? According to showrunner Mike Schur (via The Hollywood Reporter):

We've been working on their storyline (on and off) for four seasons now, and heading into this year, with the two of them contemplating parenthood, it felt like a natural time to move them into the next phase.

This is a non-answer and doesn't make any sense to me. Yet while I care... I kind of don't care, ya know? I suppose my feelings can be best summed up by the following video of an old man playing a trumpet at a donkey. (Naturally, I'm the donkey.)