i had a girl in my highschool class that, whenever someone complemented her, she would always start a discussion just to dismiss and prove that she didn't actually deserve the compliment that was made.
She was kind of a nerdy girl but in her nerdiness, she had a cute face, and she had ridiculously wide hips and a wide and fat ass which attracted the boy's attentions. She was also one of the best students in our class and her english was perfect. There also 2 or 3 boys interested in her. With this status she was a bit envied by the other girls.
However she had compulsively low self esteem (apparently at the very least) and would almost get buthurt when complimented and felt like she had to refuse any compliment made to her. For example: Someone complimented her hair in a certain day and she would be like: "No, that's not true. My hair sucks and i hate it! Stop sayin my hair looks good please!" That kind of behaviour always seemed childish to me.
i mean there's limits to hating yourself and to low self esteem. Just because you don't like yourself, or, at least, a certain trait of you body or personality i don't think you should become obssessed with it and start behaving like some maniac and make that become the bane of your existence. In that way, sure it can be childish.
As a minimum you should be able to, at least, accept other people's compliments (even if you suspect they are fake or bad intentioned) without bringing out all your frustrations.