Where the law says the site gets closed for violating, then I think the site is justified. However, the is one site that's often mentioned on here where they say no characters under 18 and the really mean it. The owner refused to post a story where one character was only 16, however, that character was not involved in any sex scenes, but it still got refused because the character was under 18.
That's the current trend now. None of the various publishing sites (Amazon, Smashwords, lulu, etc.) allow sex between any characters younger than 18, and many moderators are tired of authors trying to get around the rules, so they take an overly harsh approach.
Currently, the only country that allows underage porn is, ironically, the U.S., which has a checkered past with censorship, but they determined years ago which they could and couldn't ban, so those earlier rulings now stand (although individual DAs continue to test the waters, usually to gin support during elections). As such, about the only site currently allowing underage porn is ASSTR. Sadly, that now means that the majority of material in ASSTR consists of this material, making finding much else difficult.
SOL, in complying with Canadian law, restricted the under age stories, and when the kiddie-porn writers all left, actually saw reader satisfaction and membership numbers go up, so Lazeez isn't unhappy with the results at all. As the ASSTR example shows, the issue isn't so much what's allowed, but how what's allowed reflects on the rest of the site.