Chihaya's character fits the description for zannen (regret;alas).
When you see someone like her, you have to comment zannen. The description was used in Railgun and Haganai. It's better than telling her, "You are perfect, except you have such and such flaws". She's not likely the only character in town. As an audience, I don't think anyone can relate to her. Maybe it's youth. So, let's just enjoy their time of hot blood and foolishness.