Coop needs to go to save humanity. The thing I found annoying is that his daughter is written as a one-note character who despite being a scientist doesn't understand this and for her entire life is defined by her anger for him. This is a general problem with Nolan's often poorly conceived female characters. And I say that as someone who really likes Interstellar, what is good in that movie is so good that it makes me give it a pass for its flaws, of which I think this is the biggest.