This sounds like a good idea but how is anyone to know what is a good movie? My wife, a big fan of Tom Hanks, found "Ladykillers" and looked forward to another excellent Hanks movie. She was assaulted by language she never expected in a Hanks movie and although she fought her way through that offensive part, the same language was present through the entire movie. Who would have expected that in a Tom Hanks film? If we found that after we had bought our ticket, it would still be counted as a box office success. Nobody counts the number of people who walk out.
Tom Hanks was in Saving Private Ryan and the language was "realistic", I suppose.
Bring back the Legion of Decency.