1) That probably is a valid defense in some countries
2) It is completely reasonable to ask for an articulate link between a crime and some sort of victim, otherwise the crime shouldn't exist. "It is obvious" is only for crimes with a very obvious victim.
For child pornography, I assume the link is because people might be selling it for cash which is harder to trace and collecting it might be supporting a community through, say, ad revenue. Because while it is sick, I don't see how curating a private, personal collection could feasibly cause harm to anyone and hence it seems like a waste of money to prosecute without some sort of connection to how it is profiting CP providers.
I've thought that the countries that criminalise cartoon depictions of child porn have gone too far. It may be obscene, but possession shouldn't be a crime. Literally nobody could be suffering from it.
2.) Your opinion is at odds with the laws of virtually every country on Earth. Countries that can’t agree on things as simple as diet, or whether gay people should be allowed to live still manage to agree on this.
1) Well South Korea, Indonesia, Kazakhstan and a smattering of African countries by the look of it [0]. And the level of enforcement probably varies wildly by country.
2) I doubt you've actually read my opinion properly, it was that the link between crime and victim should be articulated on request. That is going to be a very popular opinion in the civilized world.
There’s a reason that isn’t a defense, and I hope you already understand why that is.