Well, Kobayashi is not right. Judging dragons from the human's point of view is not exactly right, but even if it so they came for calm negotiations and proposed to ask Kanna to decide, and Kobayashi is getting all worked up and calling them names, while she herself didn't even ask Kanna's opinion and decided all for herself. Kanna is not human child, she has her childish side, but she is smart and serious enough to respect her own decisions.