from my point of view, Jim saved everyone on the ship, if he did not woke up aurora then he would have killed himself after some time, because he already tried once. once he is gone there would be no one to who have seen most of the ships and know the locations of diagnostic stations, as per timeline, next would be gus to wake up and he will be at the end of his life so he cant do anything about it before he dies, and then reactor blows up and everyone dies.
only thing I don't like about this movie is be don't get to see the life they lived.