I don't think anyone would argue this "cures" the tendency - certainly I will not! But, at the very least, I can't see how it could do other than make a pedophile less likely to graduate to child molesting, to have built a strong habit of not acting on the urge - and, again, vice versa.
There are also other forms of harm than the physical. I am not myself moved to dismay by the possibility of images of my own abuse circulating on the Internet, although that may have more than anything to do with the fact that, to the best of my knowledge, no such images were made, and in any case said abuse occurred long before the dawn of the era in which such distribution became trivially simple. But I hardly imagine it is my place to tell someone who does find such a possibility - or a certainty - dismaying, that she is wrong to feel that way, or that she should not consider herself to be harmed thereby. Nor do I believe it is anyone else's place to do so.
Reinforcing the circuits to reward yourself with more porn, not with molesting children. Your whole point is exactly the kind of pseudo scientific rationalising every authoritarian uses to push their "moralistic" agenda.
Real studies have actually shown that exposure porn reduces recidivism and tendencies to molestation, except in a small class of pedophiles which already have violent tendencies.
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
While it would be a stretch to postulate that the effect of child pornography on those disposed to it exactly matches that of drugs which provoke massive dopamine release on those who take them, the effects of dopamine on sexual behavior in the human male, and its role in the brain's reward system in general, lend I think considerable plausibility to the hypothesis that engaging in pedophilic behavior centered around child pornography, and obtaining sexual satisfaction thereby, tends to potentiate further engagement in the same behavior.
[1] http://www.sciencedirect.com/science/article/pii/01497634940...
This shouldn't be surprising. Consumers of rape fetish porn are unlikely to actually rape someone, but actual rapists are likely to consume rape fetish porn. Furthermore, in countries where porn of all kinds was legalized, including child porn, enjoyed falling rates of child molestation.
The OP is making some of the same old arguments people have trotted out against porn for decades, just couched in pseudo neuroscience. The fact is, we don't understand these relationships to the degree the OP needs to justify his causal claims.
On the other hand, children are extraordinarily vulnerable to many forms of abuse, this among them. In a system of laws one of whose explicit purposes is to afford those vulnerable to mistreatment protection under law, I don't think it is on its face unreasonable to argue that children merit extraordinary protection as well. While there is perhaps a fair question to be asked around whether the sort of law under discussion actually serves that end, I would at the very least suggest anyone raising the question in a serious way be very well prepared to answer objections and counterarguments of every imaginable sort.