I think its largely due to what you are exposed to, and become used to. There was a time when the idea of loli hentai would have disgusted me. But you sit there watching lots of anime, you see attractive teenage characters. You watch more and more anime, and you see younger and younger characters that are attractive. It's not necessarily sexual, but it plants the seeds. You browse image boards like 4chan, and people are posting loli pics, and maybe you think its funny or amusing at first. Eventually, all of this stuff comes together, and you find that loli hentai is now sexually exciting for you. The things that you exposed yourself to conditioned you to it.
Japan is a nation of fucking pedophiles, but its really not a surprise to me. You can walk down the street and buy photobooks featuring junior high kids in provocative poses. Adult businessmen pay young girls to go out with them. You can buy panties out by schoolgirls out of a vending machine. In that kind of environment, the someone living in Japan would probably have a hard time NOT being a pedophile.










