Heck, a lot of people don't seem to get that at any age. I don't think this is a solid argument.
Very true re more nasty material though. IMO that should be demarked at an even deeper level than softcore or regular porn. Stuff marked as BDSM or 'extreme' or whatever should have an extra 'Are you sure you want to watch this' or w/e.
Not that it would work. The internet will internet.
Good call
It doesn't need a lot of people though. Some things in society you need to consider those miniscule chances and make the call on it.
Kids are all different and they are all pretty impressionable. We know that a lot of kids can be rebellious and curious. Peer pressure also certainly exists. We need to consider stupid scenarios such as 1 popular bloke with too much enthusiasm for it making it seem like the coolest thing and spreading between all his friends until we find that .1 percent person where a problem occurs.
The nasty stuff is an interesting argument as well. I remember people jokingly sending links to lemon party, mr hands and all sorts of all other shocking nasty stuff (do not google, NSFW, NSFL) before I even had my first regular porn site.
Also, at least when I was in highschool there were certainly some more softcore magazines out there to give the kids' imagination a kick. You know the types, models in sexy swimsuits posing but nothing really exposed. Convenient censoring and what not. It is our form of ecchi I guess. Heck, you find some of this stuff in car magazines sometimes. Some of them can be sold to 16 or younger.