My apologies if the ratings seem somewhat onerous and unnecessary... but you must understand where we're sitting as far as the site is concerned.
We apply the MPAA ratings to stories, however, since it is impossible to ensure that our readers have "parental supervision," we must take that into account when rating stories. This site depending, as it does, on donations, must ensure that we have the strongest ratings possible on our stories. We must also enforce our ratings in an effort to prove that we take this seriously and are not carelessly purveying adult material to minors.
We simply do not have the resources of a site like FF.net to withstand any legal objections to our site or its material.
Thus, yes, I can see where many of our members would consider the MA stories to be closer to PG-13 or otherwise. Still, a PG-13 or R rating would require that we are aware of parental oversight. And, here on the interwebs, we can't do that like one could in a movie theater.
Again, my apologies to anyone who is offended by the strict nature of our ratings - I can only plead that it is for the protection of the site.
~~Wiccan~~