That fact that they're sex toys based on prepubescent girls.
Right, and I think thats a perfectly normal response. I feel (or did feel) the same, but the more I contemplate it, the more I keep coming back to one unarguable fact: a doll that looks like a child, a man, a woman, an animal or anything else is still an artificial object that is not actually the thing that it looks like. I mean we (gamers at least) get angry at critics of video games who cant seem to tell the difference between a game character and a real life child or a real life adult, yet here we are with dolls, just assuming that an inanimate object should be viewed with disgust or outrage. It seems we might not be able to distinguish what is fantasy from reality, as well.
Interesting observation actually.
I wouldn't be surprised if some of the same people feeling revolted at the mere idea of child sex dolls turn around and complain about censorship in video games. If the "it's not a real woman" argument holds, then so should "it's not a real girl". They should at least be consistent with their ability (or inability) to separate reality from fiction.
Another funny observation is that most of them are for physical child abuse or "discipline" ---