Regardless of legality, hosting location or whatever else, undoubtedly the US and EU governments flag people who seek underage themed literature as possible suspects for having OTHER stuff of that nature. Who needs ADDITIONAL government monitoring?
The other angle is that if this type of thing becomes OK here, it will attract people who like that stuff and drive away the TF themed writers and readers we want. There are enough crap peddlers on the internet already, and I've seen good websites in the past get consumed in this fashion. The internet is not now the bazaar of ideas that is once was. We are no longer that strength which in old days formed the vast and complex web. The internet has divided into corporate-like mainstream websites and underground shady websites. We can either rise into the light, or descend into the darkness. I still feel that TF was more deserving to go mainstream over BDSM. We will never go mainstream if we are associated with underage BS.
Anyway, a story about a world where women have, say, penises on their head is fully subjective. The reader can determine if that is something they like or dislike. They can think about what that would be like without ever having to worry about it happening. It makes you think, even if what you think is "EWWWWW". It is that inner thought process and inner exploration that defines TF. And while the alternate world I described above would likely affect underage people in some way, it would of course never be mentioned in any detail. The reader would be left to wonder about it to themselves if they chose to, or be free to not think of it at all.
A story about underage sex is different because it could happen in real life and has. Human morality has already weighed this and 99.9% of people have found it to be wrong. These stories for that 99.9% only make the reader wonder what it would be like to burn their computer and cross the border in the middle of the night.
