Here's an article that explains the triumph of the PG and PG-13 ratings without blaming John Ashcroft:
Of the top 20 biggest box office hits of last year, all but one were rated PG or PG-13. The Santa Clause 2 was the sole G-rated film to make the list, while 8 Mile, the R-rated Eminem (news - web sites) movie, just missed at No. 21.
The PG rating appeals to movie-savvy teens who find a G rating too juvenile. PG-13 is even better, implying the movie goes about as far as it can without kids having to be taken by parents if they want to see it.
Even so, more movies are still given R ratings than any other rating:
R-rated movies have hardly died. This summer, The Matrix Reloaded became the highest-grossing R movie ever, with $268.9 million and counting. Terminator 3: Rise of the Machines opens today, and Bad Boys II on July 18. R is the most common rating, but only because so many are low-budget foreign-language films that aren't widely released, or steamy made-for-video movies.