Why is bud unhappy about being sent to live with the amoses?

Bud is unhappy about being sent to live with the Amoses because he feels unwelcome and senses their hostility towards him. He worries about being treated poorly, as he has already experienced neglect and mistreatment in his past. Additionally, Bud values his independence and struggles with the idea of being uprooted from his familiar surroundings, further contributing to his unhappiness about the situation.