Basically because he does not want to put Liesel or the Hubermanns at any more risk. Being found hidden in their basement would most certainly have grave consequences. Max also wants to actively fight the Nazis.
The Book Thief study guide contains a biography of Markus Zusak, literature essays, quiz questions, major themes, characters, and a full summary and analysis.
The Book Thief essays are academic essays for citation. These papers were written primarily by students and provide critical analysis of The Book Thief by Markus Zusak.