In "The Death of Ivan Ilych", Chapter 2 states that since Ivan's life was simple and ordinary, it was a terrible life. I think that this quote is the reason for the first chapter or everyone's reaction to his death. Since Ivan lived an ordinary and simple life, he never got to experience everything life had to offer or to really enjoy what he would have possibly wanted to do. That regret of not challenging himself in his life is what makes it terrible and people can feel bad for him because of this. The terribleness of his life stems from living a non-important life.
Also, I think that Chapter 1 describes the ordinariness of Ivan's life by the reaction of his friends. These men are suppose to be his colleagues and friends, but when the news hit them of Ivan's death, they immediately started thinking of how to fill his position and the monotonous routine they must follow to help the mourning widow. They seem almost not to care that he has past and that exemplifies the terribleness of living an ordinary and simple life.