Why does Darry react so angrily when ponyboy stays out late the outsiders?

Darry reacts angrily when Ponyboy stays out late because he feels a deep responsibility for his younger brother after their parents' death. He worries about Ponyboy's safety and the potential dangers of the world they live in, especially given the ongoing tensions between the Greasers and the Socs. Darry's anger is also rooted in his desire to enforce rules and maintain structure in their lives, as he believes that staying out late could lead to serious consequences. Ultimately, his reaction stems from concern and love, even if it sometimes comes across as harsh.