Why did the counselors pick on zero in holes?

In "Holes" by Louis Sachar, the counselors at Camp Green Lake pick on Zero because he is quiet, withdrawn, and often perceived as weak. His lack of social skills and academic struggles make him an easy target for bullying by both the counselors and the other boys. This mistreatment reflects the broader themes of isolation and the struggle for acceptance that are central to the story. Additionally, Zero's eventual friendship with Stanley Yelnats highlights the importance of loyalty and understanding in overcoming adversity.