Why is Maria so upset when Bruno keeps complaining that his father made a terrible mistake coming to Out-With?

Maria is upset because she deeply cares about Bruno and his family's well-being, and she knows that their move to Out-With was not a mistake but a decision made for their safety and security. She feels a sense of loyalty to the family and is frustrated by Bruno's inability to understand the gravity of their situation. Maria also recognizes that complaining about their circumstances can foster negativity and discontent, which she wishes to avoid for the sake of the family's unity. Her emotional response reflects her desire to protect Bruno from the harsh realities of their environment.