I believe the thinking is that minors should not have access to those kind of stories. In some states in the USA the age of consent is 18 (it's 16 in most), so I think that's why the age limit is 18 on these boards as well (though I'm not sure about that). Also, you need to be 18 to see NC-17 movies (that is movies containing graphic sex scenes) in the States.
I have no idea why this fandom is comparatively strict in regard to this issue. Most fandoms don't have password protection for nfic, just a warning. You'll have to ask those that have been around the L&C fandom longer than I have. Maybe it's specifically
because there's lots of moms with younger children and they wouldn't want their kids reading nfic.
Personally, I agree with you, but the consensus here seems to be that the nfic issue is being handled well, and I don't think it's worth a debate or fight (or possibly flame war
). Plus I'm not very involved in fanfic, so it doesn't really affect me.
