I do question the damage done to children. I agree the sexual assault and rape are harmful. As are forced or coerced sexual interactions.
But consensual sex between a child and adult is not always harmful. Especially in societies that are sexually open and permissive. There are studies and anecdotal evidence that indicate even in our society adult/child sex can be beneficial.
P.S. Since I guess I might argue this a bit, so for clarity. I am a pro-contact pedophile. I have not ever and do not plan to be sexually involved with a child (nor have most pedophiles; whether anti's or pro's). I believe that in our society (given current attitudes) the child is likely to be harmed (though it is not definite that they would be) and I do not wish to harm a child (I also wish to avoid jail time, but that is actually my secondary concern).
But I also believe that in a sexually permissive society a child can engage in a sexual relationship with an adult and benefit from it