Marjane's dad is a photographer, and he often finds himself in dangerous situations, photographing political protests. Although he's playing a small role in the revolution (someone has to document the horrors that are happening, and it's not like he can just tweet about them in the 1980s), Marji has trouble rationalizing the fact that her father is not a hero. "My father was not a hero. […] If only he had been in prison" (8.1-8.2), she says. It takes her a long time to change her narrow definition of hero.
A hero isn't just a person who goes to jail for standing up what he believes in. Marji's dad is a man who stands up for what he believes in, after all… he just happens not to get caught. Marji eventually realizes that "he loved his country as much as I did" (11.36), and just has a different way of showing it.
Because of his more thoughtful, less physical, nature, he is very skeptical. He checks everything out from two different news sources and likes hearing the other side of the story. As a result, he's a great source of information on what is really going on in Iran, both for Marjane and for us.
When Marjane returns to Iran after living in Vienna, she sees just how beaten and broken down her parents are from staying in the country. After talking to her father about the hundreds of thousands of people killed in Iran over the previous few years, she observes, "I didn't feel any real conviction in his voice. He seemed to me as blasé as my mother" (29.76).
Her father always hoped to enact social change and, well, it never happened. No wonder he is tired and worn out. The only good to come of this is that he devotes his passion and energy into Marjane. Maybe she can be the one to change the world.