Why did Billie Jo criticize the killing of rabbits?

In the story, Billie Jo criticizes the killing of rabbits because she believes that it is inhumane.
Accordingly, Mr. Romney and Mr. Noble challenge each other to a rabbit-killing duel. Each boasts that he can kill more rabbits than the other.
For his part, Mr. Noble wants to kill rabbits because they have caused much damage to his crops. Meanwhile, Mr. Romney claims that he has had more rabbit trouble than anyone in his entire county. Both men are upset that rabbits have destroyed all of their hard work.
Billie Jo sees things from a different perspective. She thinks that it is inhumane of the men to kill rabbits. Billie Jo does acknowledge, however, that the rabbits eat what they shouldn't. Being young, she does not realize that the farmers depend upon their crops to provide food and shelter for their own families.
Billie Jo agrees with her teacher, Miss Freeland, who contends that the rabbits have little choice but to eat the farmers' crops. This is because the farmers have plowed under the vegetation that the rabbits depend on for food. Despite her anger at the rabbit killings, Billie Jo consoles herself that poor families will benefit from having access to fresh meat (rabbit meat).