Why did being called white-trash with long hair offend ponyboy?

Ponyboy was offended by being called "white-trash" because it struck at his identity and social status. The term dehumanizes and marginalizes him, reinforcing societal stereotypes about class and worth. His long hair symbolizes his individuality and rebellion against societal norms, making the insult feel even more personal. Ultimately, it highlights Ponyboy's struggle with his self-image and the judgment he faces from others.