So yuu doesn't conforms himself with the temporary labels people put on him, and I totally get it. He's totally right in not accepting it, reminder that the same girls who are calling him hot are the same that on 2 volumes earlier were saying to mai that yuu was gross when she searched for him.
It's only natural for yuu, who has a great depth of knowing himself, to doubt said "compliments"
I side with him. We shouldn't define ourselves by these labels, that are like stickers. A sticker loses it's glue and falls off. It is not permanent