for little girls to be sexualized when they are just children, don't have any frame of reference, and are in the process of developing a sense of self. It is just obvious common sense that it appeals to men who are into adults. It should be self-evident that if a man is into children, then he is attracted to children, ergo those who appear to be children.
I think most people know this, hence the negative reaction to women who are legally adults but are portrayed in provocative media as being underage through full coverage under-garmets, barely there makeup, and flat shoes.

Women, mothers, and fathers all have legitimate cause for not wanting female children sexualized. It attracts predators and is psychologically harmful and destructive. I think most people cite "pedophiles" in their criticism because the term and concept carries the most extreme negative connotation. It may deter non-pedophile men from harassing or assaulting sexualized girls, and non-pedo decision makers from sexualizing young girls in their media, out of fear and shame of being associated with pedophilia.