Why does Papa say the coon trap is “unsportsmanlike”?

From the text:

A sorrowful look came over Papa's face as he ran his fingers through the soft, yellow hair. "Billy," he said, "I want you to take a hammer and pull the nails from every one of those traps. It's summertime now and their fur isn't any good. Besides, I don't think this is very sportsmanlike. The coon doesn't have a chance. It's all right this time. You needed this one, but from now on I want you to catch them with your dogs. That way they have a fifty-fifty chance."