We classify attraction toward adult humans as natural, and toward things that are not adult humans as abnormal, which includes children, and when the attraction is solely to that and not at all to adult humans it's a dysfunction. That's what pedophilia is. A pedophile who acts on this attraction is likely to break a law designed to protect children eg laws against child abuse or child porn.

Incest is a different matter, these laws are mostly religious in origin as it was seen as a sin, and it's also fairly entrenched a social taboo - but even in the secular world it's seen as avoiding reproduction between two people when there is not enough genetic diversity. So there's no compelling reason to repeal incest laws where they exist.