I don't think Berlin is trying to justify adult-child sex. He is simply stating that if we are to prevent it, we must study it. Any hunter will tell you that you must study your prey to be successful. It is also true that merely passing laws outlawing something, no matter how draconian the punishment, does not equate with stopping or minimizing the behavior and in fact, may often make it worse. For example, prohibition was a roaring failure that simply pumped up armed gangs and widespread disrespect for the law. What does work rather well is Alcoholics Anonymous, where alcoholics are put at ease to discuss their habits and the damage it has caused. In an atmosphere that acknowledges the disease and proscribes a program of treatment, many of the most hopeless alcoholics have been reformed.

He is also trying to understand the dynamics of the organizations that have failed to protect the children. Now I will say, the ongoing rabid reaction of Penn State fans in defending Joe Paterno is hard to fathom, it really does boil down to them valuing football more than children.
God grant me
The Serenity to accept the things I cannot change,
The Courage to change the things I can,
And the Wisdom to know the difference.