MPAA'S Rating Confusion

At the end of the NY Times review of "The Day After Tomorrow", a disaster movie that is said to be a lovely disaster in and of itself, this is the summary about the movie's rating and questionable material:

"The Day After Tomorrow" is rated Pg-13. Millions of people die, but nobody swears, copulates, undresses or takes drugs.

Um....Ok. So millions of people dying is fine as long as none of them have last minute sex. Aha.

I think that South Park creators Matt Stone and Trey Parker summed this up nicely in a line uttered by Kyle's Mom, "Remember what the MPAA says: Horrific, Deplorable violence is okay, as long as people don't say any naughty words!"