Because it more impact full if you talk about girls, it more shocking, as if it was more unacceptable because its girls.
In Europe and the US, the child sexual exploitation offenders are most commonly white, but people only get outraged when they are not white. It feeds into the narrative that immigrants are bad people.
"Hordes of migrants invading the US to kill, rape women and girls, eat dogs, cats and geese, and illegally vote for Kamala Harris."
When in reality they are the ones being killed, raped and abused.
What would the US do without them to pick fruits and vegetables, slaughter animals and package meat, clean houses and offices, deliver food and parcels, drive them around,...