I'm surprised you think whatever intuitions you may have developed on such a complicated subject as human sexuality and neurology actually mean anything. Plenty of people with just as much confidence as you that ordinary porn was harmful were similarly surprised decades ago when rape and sexual assault rates continued to fall despite the continued spread of porn. Why would pedophilia be any different than any other sexual fetish in this respect [1]? In fact, there exists direct evidence that legalized child porn reduces sexual abuse against children [3].

All of the studies purporting to demonstrate links between possession of child porn and child molestation are plagued with methodological errors [2]. This issue is so emotionally charged that most of the science around it is garbage. The stigma against child porn is no different than claiming that consumers of staged rape fetish porn must all be closet rapists, and viewing this porn will simply make them act on it. It's a patently absurd claim.

About the only possessors of child porn that are at high risk of molesting a child are the ones that actually produce it, and so had already sexual abused children [4].

[1] http://www.jstor.org/stable/1123799?seq=1#page_scan_tab_cont...

[2] https://www.fd.org/docs/training-materials/2012/FJC2012/Chil...

[3] http://link.springer.com/article/10.1007%2Fs10508-010-9696-y

[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716325/

Thanks very much for the links, and for the substantive comment! I look forward to reviewing them at my earliest opportunity.